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  25. <div class="section">
  26. <div class="titlepage"><div><div><h3 class="title">
  27. <a name="boost_multiprecision.ref.number"></a><a class="link" href="number.html" title="number">number</a>
  28. </h3></div></div></div>
  29. <h5>
  30. <a name="boost_multiprecision.ref.number.h0"></a>
  31. <span class="phrase"><a name="boost_multiprecision.ref.number.synopsis"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.synopsis">Synopsis</a>
  32. </h5>
  33. <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">multiprecision</span><span class="special">{</span>
  34. <span class="keyword">enum</span> <span class="identifier">expression_template_option</span> <span class="special">{</span> <span class="identifier">et_on</span> <span class="special">=</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">et_off</span> <span class="special">=</span> <span class="number">0</span> <span class="special">};</span>
  35. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">&gt;</span> <span class="keyword">struct</span> <span class="identifier">expression_template_default</span>
  36. <span class="special">{</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">expression_template_option</span> <span class="identifier">value</span> <span class="special">=</span> <span class="identifier">et_on</span><span class="special">;</span> <span class="special">};</span>
  37. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span> <span class="special">=</span> <span class="identifier">expression_template_default</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">&gt;</span>
  38. <span class="keyword">class</span> <span class="identifier">number</span>
  39. <span class="special">{</span>
  40. <span class="keyword">public</span><span class="special">:</span>
  41. <span class="keyword">typedef</span> <span class="identifier">Backend</span> <span class="identifier">backend_type</span><span class="special">;</span>
  42. <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">component_type</span><span class="special">&lt;</span><span class="identifier">self_type</span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">value_type</span><span class="special">;</span>
  43. <span class="identifier">number</span><span class="special">();</span>
  44. <span class="identifier">number</span><span class="special">(</span><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span><span class="special">);</span>
  45. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span><span class="special">);</span>
  46. <span class="identifier">number</span><span class="special">&amp;</span> <span class="identifier">assign</span><span class="special">(</span><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span><span class="special">);</span>
  47. <span class="comment">// Member operators</span>
  48. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">+=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  49. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">-=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  50. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">*=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  51. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">/=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  52. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">++();</span>
  53. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">--();</span>
  54. <span class="identifier">number</span> <span class="keyword">operator</span><span class="special">++(</span><span class="keyword">int</span><span class="special">);</span>
  55. <span class="identifier">number</span> <span class="keyword">operator</span><span class="special">--(</span><span class="keyword">int</span><span class="special">);</span>
  56. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">%=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  57. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">&amp;=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  58. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">|=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  59. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">^=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  60. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">&lt;&lt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  61. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">&gt;&gt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  62. <span class="comment">// Use in Boolean context:</span>
  63. <span class="keyword">operator</span> <span class="emphasis"><em>convertible-to-bool-type</em></span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  64. <span class="comment">// swap:</span>
  65. <span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">number</span><span class="special">&amp;</span> <span class="identifier">other</span><span class="special">);</span>
  66. <span class="comment">// Sign:</span>
  67. <span class="keyword">bool</span> <span class="identifier">is_zero</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  68. <span class="keyword">int</span> <span class="identifier">sign</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  69. <span class="comment">// string conversion:</span>
  70. <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">str</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  71. <span class="comment">// Generic conversion mechanism</span>
  72. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  73. <span class="identifier">T</span> <span class="identifier">convert_to</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  74. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  75. <span class="keyword">explicit</span> <span class="keyword">operator</span> <span class="identifier">T</span> <span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  76. <span class="comment">// precision control:</span>
  77. <span class="keyword">static</span> <span class="keyword">unsigned</span> <span class="identifier">default_precision</span><span class="special">();</span>
  78. <span class="keyword">static</span> <span class="keyword">void</span> <span class="identifier">default_precision</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="identifier">digits10</span><span class="special">);</span>
  79. <span class="keyword">unsigned</span> <span class="identifier">precision</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  80. <span class="keyword">void</span> <span class="identifier">precision</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="identifier">digits10</span><span class="special">);</span>
  81. <span class="comment">// Comparison:</span>
  82. <span class="keyword">int</span> <span class="identifier">compare</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">&gt;&amp;</span> <span class="identifier">o</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
  83. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">V</span><span class="special">&gt;</span>
  84. <span class="keyword">typename</span> <span class="identifier">enable_if</span><span class="special">&lt;</span><span class="identifier">is_convertible</span><span class="special">&lt;</span><span class="identifier">V</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span> <span class="special">&gt;,</span> <span class="keyword">int</span><span class="special">&gt;::</span><span class="identifier">type</span>
  85. <span class="identifier">compare</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">V</span><span class="special">&amp;</span> <span class="identifier">o</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
  86. <span class="comment">// real and imaginary parts:</span>
  87. <span class="identifier">value_type</span> <span class="identifier">real</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  88. <span class="identifier">value_type</span> <span class="identifier">imag</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  89. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  90. <span class="keyword">void</span> <span class="identifier">real</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">val</span><span class="special">);</span>
  91. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  92. <span class="keyword">void</span> <span class="identifier">imag</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">val</span><span class="special">);</span>
  93. <span class="comment">// Access to the underlying implementation:</span>
  94. <span class="identifier">Backend</span><span class="special">&amp;</span> <span class="identifier">backend</span><span class="special">();</span>
  95. <span class="keyword">const</span> <span class="identifier">Backend</span><span class="special">&amp;</span> <span class="identifier">backend</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  96. <span class="special">};</span>
  97. <span class="comment">// Non member operators:</span>
  98. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">+(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  99. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">-(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  100. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">+(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  101. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">-(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  102. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">*(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  103. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">/(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  104. <span class="comment">// Integer only operations:</span>
  105. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">%(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  106. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">&amp;(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  107. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">|(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  108. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">^(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  109. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">&lt;&lt;(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  110. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">&gt;&gt;(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  111. <span class="comment">// Comparison operators:</span>
  112. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">==(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  113. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  114. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&lt;</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  115. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&gt;</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  116. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&lt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  117. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&gt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  118. <span class="comment">// Swap:</span>
  119. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  120. <span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  121. <span class="comment">// iostream support:</span>
  122. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  123. <span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">&lt;&lt;</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="identifier">os</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  124. <span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">&lt;&lt;</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="identifier">os</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>unmentionable-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  125. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  126. <span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">&gt;&gt;</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span><span class="special">&amp;</span> <span class="identifier">is</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  127. <span class="comment">// Arithmetic with a higher precision result:</span>
  128. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ResultType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Source1</span> <span class="keyword">class</span> <span class="identifier">Source2</span><span class="special">&gt;</span>
  129. <span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">add</span><span class="special">(</span><span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">result</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source1</span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source2</span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  130. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ResultType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Source1</span> <span class="keyword">class</span> <span class="identifier">Source2</span><span class="special">&gt;</span>
  131. <span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">subtract</span><span class="special">(</span><span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">result</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source1</span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source2</span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  132. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ResultType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Source1</span> <span class="keyword">class</span> <span class="identifier">Source2</span><span class="special">&gt;</span>
  133. <span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">multiply</span><span class="special">(</span><span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">result</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source1</span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source2</span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  134. <span class="comment">// min and max overloads:</span>
  135. <span class="emphasis"><em>number</em></span> <span class="identifier">min</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  136. <span class="emphasis"><em>number</em></span> <span class="identifier">max</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  137. <span class="comment">// C99 Non-member function standard library support:</span>
  138. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">abs</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  139. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">acos</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  140. <span class="emphasis"><em>number</em></span> <span class="identifier">acosh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  141. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">asin</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  142. <span class="emphasis"><em>number</em></span> <span class="identifier">asinh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  143. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">atan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  144. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">atan2</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  145. <span class="emphasis"><em>number</em></span> <span class="identifier">atanh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  146. <span class="emphasis"><em>number</em></span> <span class="identifier">cbrt</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  147. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">ceil</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  148. <span class="emphasis"><em>number</em></span> <span class="identifier">copysign</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  149. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">cos</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  150. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">cosh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  151. <span class="emphasis"><em>number</em></span> <span class="identifier">erf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  152. <span class="emphasis"><em>number</em></span> <span class="identifier">erfc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  153. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">exp</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  154. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">exp2</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  155. <span class="emphasis"><em>number</em></span> <span class="identifier">expm1</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  156. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fabs</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  157. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fdim</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  158. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">floor</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  159. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fma</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  160. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fmin</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  161. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fmax</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  162. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fmod</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  163. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">frexp</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">*);</span>
  164. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">hypot</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  165. <span class="emphasis"><em>integer-type</em></span> <span class="identifier">ilogb</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  166. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">ldexp</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">);</span>
  167. <span class="emphasis"><em>number</em></span> <span class="identifier">lgamma</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  168. <span class="keyword">long</span> <span class="keyword">long</span> <span class="identifier">llrint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  169. <span class="keyword">long</span> <span class="keyword">long</span> <span class="identifier">llround</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  170. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">log</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  171. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">log2</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  172. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">log10</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  173. <span class="emphasis"><em>number</em></span> <span class="identifier">log1p</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  174. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">logb</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  175. <span class="keyword">long</span> <span class="identifier">lrint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  176. <span class="keyword">long</span> <span class="identifier">lround</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  177. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">modf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  178. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">nearbyint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  179. <span class="emphasis"><em>number</em></span> <span class="identifier">nextafter</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  180. <span class="emphasis"><em>number</em></span> <span class="identifier">nexttoward</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  181. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">pow</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  182. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">remainder</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  183. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">remquo</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">*);</span>
  184. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">rint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  185. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">round</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  186. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">scalbn</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">);</span>
  187. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">scalbln</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">);</span>
  188. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sin</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  189. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sinh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  190. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sqrt</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  191. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">tan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  192. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">tanh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  193. <span class="emphasis"><em>number</em></span> <span class="identifier">tgamma</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  194. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">trunc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  195. <span class="keyword">int</span> <span class="identifier">fpclassify</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  196. <span class="keyword">bool</span> <span class="identifier">isfinite</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  197. <span class="keyword">bool</span> <span class="identifier">isinf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  198. <span class="keyword">bool</span> <span class="identifier">isnan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  199. <span class="keyword">bool</span> <span class="identifier">isnormal</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  200. <span class="keyword">int</span> <span class="identifier">signbit</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  201. <span class="keyword">bool</span> <span class="identifier">isgreater</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  202. <span class="keyword">bool</span> <span class="identifier">isgreaterequal</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  203. <span class="keyword">bool</span> <span class="identifier">isless</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  204. <span class="keyword">bool</span> <span class="identifier">islessequal</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  205. <span class="keyword">bool</span> <span class="identifier">islessgreater</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  206. <span class="keyword">bool</span> <span class="identifier">isunordered</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  207. <span class="comment">// Complex number functions:</span>
  208. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">real</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  209. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">imag</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  210. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">abs</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  211. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">arg</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  212. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">norm</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  213. <span class="emphasis"><em>number</em></span> <span class="identifier">conj</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  214. <span class="emphasis"><em>number</em></span> <span class="identifier">proj</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  215. <span class="emphasis"><em>number</em></span> <span class="identifier">polar</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  216. <span class="comment">// Misc other common C library functions:</span>
  217. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">itrunc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  218. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">ltrunc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  219. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">lltrunc</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  220. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">iround</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  221. <span class="emphasis"><em>number</em></span> <span class="identifier">changesign</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  222. <span class="emphasis"><em>number</em></span> <span class="identifier">copysign</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  223. <span class="comment">// Traits support:</span>
  224. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  225. <span class="keyword">struct</span> <span class="identifier">component_type</span><span class="special">;</span>
  226. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  227. <span class="keyword">struct</span> <span class="identifier">number_category</span><span class="special">;</span>
  228. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  229. <span class="keyword">struct</span> <span class="identifier">is_number</span><span class="special">;</span>
  230. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  231. <span class="keyword">struct</span> <span class="identifier">is_number_expression</span><span class="special">;</span>
  232. <span class="comment">// Integer specific functions:</span>
  233. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">gcd</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  234. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">lcm</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  235. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">pow</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">unsigned</span><span class="special">);</span>
  236. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">powm</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">p</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">m</span><span class="special">);</span>
  237. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sqrt</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  238. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  239. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">EXpressionTemplates</span><span class="special">&gt;</span> <span class="identifier">sqrt</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">EXpressionTemplates</span><span class="special">&gt;&amp;);</span>
  240. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  241. <span class="keyword">void</span> <span class="identifier">divide_qr</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">y</span><span class="special">,</span>
  242. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">q</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  243. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Integer</span><span class="special">&gt;</span>
  244. <span class="identifier">Integer</span> <span class="identifier">integer_modulus</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">Integer</span> <span class="identifier">val</span><span class="special">);</span>
  245. <span class="keyword">unsigned</span> <span class="identifier">lsb</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">);</span>
  246. <span class="keyword">unsigned</span> <span class="identifier">msb</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">);</span>
  247. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  248. <span class="keyword">bool</span> <span class="identifier">bit_test</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  249. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  250. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">bit_set</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  251. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  252. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">bit_unset</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  253. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  254. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">bit_flip</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  255. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Engine</span><span class="special">&gt;</span>
  256. <span class="keyword">bool</span> <span class="identifier">miller_rabin_test</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">n</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">trials</span><span class="special">,</span> <span class="identifier">Engine</span><span class="special">&amp;</span> <span class="identifier">gen</span><span class="special">);</span>
  257. <span class="keyword">bool</span> <span class="identifier">miller_rabin_test</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">n</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">trials</span><span class="special">);</span>
  258. <span class="comment">// Rational number support:</span>
  259. <span class="keyword">typename</span> <span class="identifier">component_type</span><span class="special">&lt;</span><span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">numerator</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  260. <span class="keyword">typename</span> <span class="identifier">component_type</span><span class="special">&lt;</span><span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">denominator</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  261. <span class="special">}}</span> <span class="comment">// namespaces</span>
  262. <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span><span class="special">{</span>
  263. <span class="comment">// Boost.Math interoperability functions:</span>
  264. <span class="keyword">int</span> <span class="identifier">fpclassify</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  265. <span class="keyword">bool</span> <span class="identifier">isfinite</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  266. <span class="keyword">bool</span> <span class="identifier">isnan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  267. <span class="keyword">bool</span> <span class="identifier">isinf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  268. <span class="keyword">bool</span> <span class="identifier">isnormal</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  269. <span class="special">}}</span> <span class="comment">// namespaces</span>
  270. <span class="comment">// numeric_limits support:</span>
  271. <span class="keyword">namespace</span> <span class="identifier">std</span><span class="special">{</span>
  272. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  273. <span class="keyword">struct</span> <span class="identifier">numeric_limits</span><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">multiprecision</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span> <span class="special">&gt;</span>
  274. <span class="special">{</span>
  275. <span class="comment">/* Usual members here */</span>
  276. <span class="special">};</span>
  277. <span class="special">}</span>
  278. </pre>
  279. <h5>
  280. <a name="boost_multiprecision.ref.number.h1"></a>
  281. <span class="phrase"><a name="boost_multiprecision.ref.number.description"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.description">Description</a>
  282. </h5>
  283. <pre class="programlisting"><span class="keyword">enum</span> <span class="identifier">expression_template_option</span> <span class="special">{</span> <span class="identifier">et_on</span> <span class="special">=</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">et_off</span> <span class="special">=</span> <span class="number">0</span> <span class="special">};</span>
  284. </pre>
  285. <p>
  286. This enumerated type is used to specify whether expression templates are
  287. turned on (et_on) or turned off (et_off).
  288. </p>
  289. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">&gt;</span> <span class="keyword">struct</span> <span class="identifier">expression_template_default</span>
  290. <span class="special">{</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">expression_template_option</span> <span class="identifier">value</span> <span class="special">=</span> <span class="identifier">et_on</span><span class="special">;</span> <span class="special">};</span>
  291. </pre>
  292. <p>
  293. This traits class specifies the default expression template option to be
  294. used with a particular Backend type. It defaults to <code class="computeroutput"><span class="identifier">et_on</span></code>.
  295. </p>
  296. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span> <span class="special">=</span> <span class="identifier">expression_template_default</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">&gt;</span>
  297. <span class="keyword">class</span> <span class="identifier">number</span><span class="special">;</span>
  298. </pre>
  299. <p>
  300. Class <code class="computeroutput"><span class="identifier">number</span></code> has two template
  301. arguments:
  302. </p>
  303. <div class="variablelist">
  304. <p class="title"><b></b></p>
  305. <dl class="variablelist">
  306. <dt><span class="term">Backend</span></dt>
  307. <dd><p>
  308. The actual arithmetic back-end that does all the work.
  309. </p></dd>
  310. <dt><span class="term">ExpressionTemplates</span></dt>
  311. <dd><p>
  312. A Boolean value: when <code class="computeroutput"><span class="identifier">et_on</span></code>,
  313. then expression templates are enabled, otherwise when set to <code class="computeroutput"><span class="identifier">et_off</span></code> they are disabled. The default
  314. for this parameter is computed via the traits class <code class="computeroutput"><span class="identifier">expression_template_default</span></code>
  315. whose member <code class="computeroutput"><span class="identifier">value</span></code>
  316. defaults to <code class="computeroutput"><span class="identifier">et_on</span></code> unless
  317. the traits class is specialized for a particular backend.
  318. </p></dd>
  319. </dl>
  320. </div>
  321. <pre class="programlisting"><span class="identifier">number</span><span class="special">();</span>
  322. <span class="identifier">number</span><span class="special">(</span><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span><span class="special">);</span>
  323. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span><span class="special">);</span>
  324. <span class="identifier">number</span><span class="special">&amp;</span> <span class="identifier">assign</span><span class="special">(</span><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span><span class="special">);</span>
  325. </pre>
  326. <p>
  327. Type <code class="computeroutput"><span class="identifier">number</span></code> is default constructible,
  328. and both copy constructible and assignable from:
  329. </p>
  330. <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  331. <li class="listitem">
  332. Itself.
  333. </li>
  334. <li class="listitem">
  335. An expression template which is the result of one of the arithmetic operators.
  336. </li>
  337. <li class="listitem">
  338. Any builtin arithmetic type, as long as the result would not be lossy
  339. (for example float to integer conversion).
  340. </li>
  341. <li class="listitem">
  342. Any type that the Backend is implicitly constructible or assignable from.
  343. </li>
  344. <li class="listitem">
  345. An rvalue reference to another <code class="computeroutput"><span class="identifier">number</span></code>.
  346. Move-semantics are used for construction if the backend also supports
  347. rvalue reference construction. In the case of assignment, move semantics
  348. are always supported when the argument is an rvalue reference irrespective
  349. of the backend.
  350. </li>
  351. <li class="listitem">
  352. Any type in the same family, as long as no loss of precision is involved.
  353. For example from <code class="computeroutput"><span class="identifier">int128_t</span></code>
  354. to <code class="computeroutput"><span class="identifier">int256_t</span></code>, or <code class="computeroutput"><span class="identifier">cpp_dec_float_50</span></code> to <code class="computeroutput"><span class="identifier">cpp_dec_float_100</span></code>.
  355. </li>
  356. </ul></div>
  357. <p>
  358. Type <code class="computeroutput"><span class="identifier">number</span></code> is explicitly
  359. constructible from:
  360. </p>
  361. <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  362. <li class="listitem">
  363. Any type mentioned above.
  364. </li>
  365. <li class="listitem">
  366. A <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> or any type which is convertible
  367. to <code class="computeroutput"><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span></code>.
  368. </li>
  369. <li class="listitem">
  370. Any arithmetic type (including those that would result in lossy conversions).
  371. </li>
  372. <li class="listitem">
  373. Any type in the same family, including those that result in loss of precision.
  374. </li>
  375. <li class="listitem">
  376. Any type that the Backend is explicitly constructible from.
  377. </li>
  378. <li class="listitem">
  379. Any pair of types for which a generic interconversion exists: that is
  380. from integer to integer, integer to rational, integer to float, rational
  381. to rational, rational to float, or float to float.
  382. </li>
  383. </ul></div>
  384. <p>
  385. The assign member function is available for any type for which an explicit
  386. converting constructor exists. It is intended to be used where a temporary
  387. generated from an explicit assignment would be expensive, for example:
  388. </p>
  389. <pre class="programlisting"><span class="identifier">mpfr_float_50</span> <span class="identifier">f50</span><span class="special">;</span>
  390. <span class="identifier">mpfr_float_100</span> <span class="identifier">f100</span><span class="special">;</span>
  391. <span class="identifier">f50</span> <span class="special">=</span> <span class="keyword">static_cast</span><span class="special">&lt;</span><span class="identifier">mpfr_float_50</span><span class="special">&gt;(</span><span class="identifier">f100</span><span class="special">);</span> <span class="comment">// explicit cast create a temporary</span>
  392. <span class="identifier">f50</span><span class="special">.</span><span class="identifier">assign</span><span class="special">(</span><span class="identifier">f100</span><span class="special">);</span> <span class="comment">// explicit call to assign create no temporary</span>
  393. </pre>
  394. <p>
  395. In addition, if the type has multiple components (for example rational or
  396. complex number types), then there is a two argument constructor:
  397. </p>
  398. <pre class="programlisting"><span class="identifier">number</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="identifier">arg2</span><span class="special">);</span>
  399. </pre>
  400. <p>
  401. Where the two args must either be arithmetic types, or types that are convertible
  402. to the two components of <code class="computeroutput"><span class="keyword">this</span></code>.
  403. </p>
  404. <p>
  405. Finally, when the type has a variable precision, then there are constructors:
  406. </p>
  407. <pre class="programlisting"><span class="identifier">number</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="identifier">precision</span><span class="special">);</span>
  408. <span class="identifier">number</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="identifier">arg2</span><span class="special">,</span> <span class="identifier">precision</span><span class="special">);</span>
  409. </pre>
  410. <p>
  411. Where <code class="computeroutput"><span class="identifier">precision</span></code> is an unsigned
  412. value, the 2 arg version is active for scalar types and/or copy-construction
  413. with specific precision, and the 3-arg version for complex types.
  414. </p>
  415. <p>
  416. Likewise <code class="computeroutput"><span class="identifier">assign</span></code> has a 2-arg
  417. overloaded, with the second argument being the precision.
  418. </p>
  419. <pre class="programlisting"><span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">+=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  420. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">-=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  421. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">*=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  422. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">/=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  423. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">++();</span>
  424. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">--();</span>
  425. <span class="identifier">number</span> <span class="keyword">operator</span><span class="special">++(</span><span class="keyword">int</span><span class="special">);</span>
  426. <span class="identifier">number</span> <span class="keyword">operator</span><span class="special">--(</span><span class="keyword">int</span><span class="special">);</span>
  427. <span class="comment">// Integer only operations:</span>
  428. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">%=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  429. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">&amp;=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  430. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">|=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  431. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">^=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  432. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">&lt;&lt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  433. <span class="identifier">number</span><span class="special">&amp;</span> <span class="keyword">operator</span><span class="special">&gt;&gt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  434. </pre>
  435. <p>
  436. These operators all take their usual arithmetic meanings.
  437. </p>
  438. <p>
  439. The arguments to these operators is either:
  440. </p>
  441. <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  442. <li class="listitem">
  443. Another <code class="computeroutput"><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span>
  444. <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span></code>.
  445. </li>
  446. <li class="listitem">
  447. An expression template derived from <code class="computeroutput"><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">&gt;</span></code>.
  448. </li>
  449. <li class="listitem">
  450. Any type implicitly convertible to <code class="computeroutput"><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span></code>, including some other instance of
  451. class <code class="computeroutput"><span class="identifier">number</span></code>.
  452. </li>
  453. </ul></div>
  454. <p>
  455. For the left and right shift operations, the argument must be a builtin integer
  456. type with a positive value (negative values result in a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span></code>
  457. being thrown).
  458. </p>
  459. <pre class="programlisting"><span class="keyword">operator</span> <span class="emphasis"><em>convertible-to-bool-type</em></span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  460. </pre>
  461. <p>
  462. Returns an <span class="emphasis"><em>unmentionable-type</em></span> that is usable in Boolean
  463. contexts (this allows <code class="computeroutput"><span class="identifier">number</span></code>
  464. to be used in any Boolean context - if statements, conditional statements,
  465. or as an argument to a logical operator - without type <code class="computeroutput"><span class="identifier">number</span></code>
  466. being convertible to type <code class="computeroutput"><span class="keyword">bool</span></code>.
  467. </p>
  468. <p>
  469. This operator also enables the use of <code class="computeroutput"><span class="identifier">number</span></code>
  470. with any of the following operators: <code class="computeroutput"><span class="special">!</span></code>,
  471. <code class="computeroutput"><span class="special">||</span></code>, <code class="computeroutput"><span class="special">&amp;&amp;</span></code>
  472. and <code class="computeroutput"><span class="special">?:</span></code>.
  473. </p>
  474. <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">number</span><span class="special">&amp;</span> <span class="identifier">other</span><span class="special">);</span>
  475. </pre>
  476. <p>
  477. Swaps <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
  478. with <code class="computeroutput"><span class="identifier">other</span></code>.
  479. </p>
  480. <pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">is_zero</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  481. </pre>
  482. <p>
  483. Returns <code class="computeroutput"><span class="keyword">true</span></code> is <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is zero,
  484. otherwise <code class="computeroutput"><span class="keyword">false</span></code>.
  485. </p>
  486. <pre class="programlisting"><span class="keyword">int</span> <span class="identifier">sign</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  487. </pre>
  488. <p>
  489. Returns a value less than zero if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is negative, a value greater than zero
  490. if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
  491. is positive, and zero if <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
  492. is zero.
  493. </p>
  494. <pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">str</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="identifier">precision</span><span class="special">,</span> <span class="keyword">bool</span> <span class="identifier">scientific</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
  495. </pre>
  496. <p>
  497. Returns the number formatted as a string, with at least <span class="emphasis"><em>precision</em></span>
  498. digits, and in scientific format if <span class="emphasis"><em>scientific</em></span> is true.
  499. </p>
  500. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  501. <span class="identifier">T</span> <span class="identifier">convert_to</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  502. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  503. <span class="keyword">explicit</span> <span class="keyword">operator</span> <span class="identifier">T</span> <span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  504. </pre>
  505. <p>
  506. Provides a generic conversion mechanism to convert <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> to type <code class="computeroutput"><span class="identifier">T</span></code>.
  507. Type <code class="computeroutput"><span class="identifier">T</span></code> may be any arithmetic
  508. type. Optionally other types may also be supported by specific <code class="computeroutput"><span class="identifier">Backend</span></code> types.
  509. </p>
  510. <pre class="programlisting"><span class="keyword">static</span> <span class="keyword">unsigned</span> <span class="identifier">default_precision</span><span class="special">();</span>
  511. <span class="keyword">static</span> <span class="keyword">void</span> <span class="identifier">default_precision</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="identifier">digits10</span><span class="special">);</span>
  512. <span class="keyword">unsigned</span> <span class="identifier">precision</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  513. <span class="keyword">void</span> <span class="identifier">precision</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="identifier">digits10</span><span class="special">);</span>
  514. </pre>
  515. <p>
  516. These functions are only available if the Backend template parameter supports
  517. runtime changes to precision. They get and set the default precision and
  518. the precision of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
  519. respectively.
  520. </p>
  521. <pre class="programlisting"><span class="keyword">int</span> <span class="identifier">compare</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">o</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
  522. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">V</span><span class="special">&gt;</span>
  523. <span class="keyword">typename</span> <span class="identifier">enable_if</span><span class="special">&lt;</span><span class="identifier">is_convertible</span><span class="special">&lt;</span><span class="identifier">V</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span> <span class="special">&gt;,</span> <span class="keyword">int</span><span class="special">&gt;::</span><span class="identifier">type</span>
  524. <span class="identifier">compare</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">V</span><span class="special">&amp;</span> <span class="identifier">other</span><span class="special">)</span><span class="keyword">const</span><span class="special">;</span>
  525. </pre>
  526. <p>
  527. Returns:
  528. </p>
  529. <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  530. <li class="listitem">
  531. A value less that 0 for <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span> <span class="special">&lt;</span> <span class="identifier">other</span></code>
  532. </li>
  533. <li class="listitem">
  534. A value greater that 0 for <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span> <span class="special">&gt;</span> <span class="identifier">other</span></code>
  535. </li>
  536. <li class="listitem">
  537. <p class="simpara">
  538. Zero for <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span>
  539. <span class="special">==</span> <span class="identifier">other</span></code>
  540. </p>
  541. <pre class="programlisting"><span class="identifier">value_type</span> <span class="identifier">real</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  542. <span class="identifier">value_type</span> <span class="identifier">imag</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  543. </pre>
  544. </li>
  545. </ul></div>
  546. <p>
  547. These return the real and imaginary parts respectively. If the number is
  548. not a complex type, then the imaginary part is always zero.
  549. </p>
  550. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  551. <span class="keyword">void</span> <span class="identifier">real</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">val</span><span class="special">);</span>
  552. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  553. <span class="keyword">void</span> <span class="identifier">imag</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">val</span><span class="special">);</span>
  554. </pre>
  555. <p>
  556. These set the real and imaginary parts respectively of the number. If the
  557. number is not a complex type, then setting the real part is equivalent to
  558. assignment, and attempting to set the imaginary part will result in a compile
  559. time error.
  560. </p>
  561. <pre class="programlisting"><span class="identifier">Backend</span><span class="special">&amp;</span> <span class="identifier">backend</span><span class="special">();</span>
  562. <span class="keyword">const</span> <span class="identifier">Backend</span><span class="special">&amp;</span> <span class="identifier">backend</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span>
  563. </pre>
  564. <p>
  565. Returns the underlying back-end instance used by <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>.
  566. </p>
  567. <h5>
  568. <a name="boost_multiprecision.ref.number.h2"></a>
  569. <span class="phrase"><a name="boost_multiprecision.ref.number.non_member_operators"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.non_member_operators">Non-member
  570. operators</a>
  571. </h5>
  572. <pre class="programlisting"><span class="comment">// Non member operators:</span>
  573. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">+(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  574. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">-(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  575. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">+(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  576. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">-(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  577. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">*(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  578. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">/(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  579. <span class="comment">// Integer only operations:</span>
  580. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">%(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  581. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">&amp;(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  582. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">|(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  583. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">^(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  584. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">&lt;&lt;(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  585. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="keyword">operator</span><span class="special">&gt;&gt;(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>integer-type</em></span><span class="special">&amp;);</span>
  586. <span class="comment">// Comparison operators:</span>
  587. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">==(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  588. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  589. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&lt;</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  590. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&gt;</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  591. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&lt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  592. <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">&gt;=(</span><span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>see-below</em></span><span class="special">&amp;);</span>
  593. </pre>
  594. <p>
  595. These operators all take their usual arithmetic meanings.
  596. </p>
  597. <p>
  598. The arguments to these functions must contain at least one of the following:
  599. </p>
  600. <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  601. <li class="listitem">
  602. A <code class="computeroutput"><span class="identifier">number</span></code>.
  603. </li>
  604. <li class="listitem">
  605. An expression template type derived from <code class="computeroutput"><span class="identifier">number</span></code>.
  606. </li>
  607. <li class="listitem">
  608. Any type for which <code class="computeroutput"><span class="identifier">number</span></code>
  609. has an implicit constructor - for example a builtin arithmetic type.
  610. </li>
  611. </ul></div>
  612. <p>
  613. The return type of these operators is either:
  614. </p>
  615. <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  616. <li class="listitem">
  617. An <span class="emphasis"><em>unmentionable-type</em></span> expression template type when
  618. <code class="computeroutput"><span class="identifier">ExpressionTemplates</span></code> is
  619. <code class="computeroutput"><span class="keyword">true</span></code>.
  620. </li>
  621. <li class="listitem">
  622. Type <code class="computeroutput"><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span>
  623. <span class="identifier">et_off</span><span class="special">&gt;</span></code>
  624. when <code class="computeroutput"><span class="identifier">ExpressionTemplates</span></code>
  625. is <code class="computeroutput"><span class="keyword">false</span></code>.
  626. </li>
  627. <li class="listitem">
  628. Type <code class="computeroutput"><span class="keyword">bool</span></code> if the operator
  629. is a comparison operator.
  630. </li>
  631. </ul></div>
  632. <p>
  633. Finally note that the second argument to the left and right shift operations
  634. must be a builtin integer type, and that the argument must be positive (negative
  635. arguments result in a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span></code>
  636. being thrown).
  637. </p>
  638. <h5>
  639. <a name="boost_multiprecision.ref.number.h3"></a>
  640. <span class="phrase"><a name="boost_multiprecision.ref.number.swap"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.swap">swap</a>
  641. </h5>
  642. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  643. <span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  644. </pre>
  645. <p>
  646. Swaps <code class="computeroutput"><span class="identifier">a</span></code> and <code class="computeroutput"><span class="identifier">b</span></code>.
  647. </p>
  648. <h5>
  649. <a name="boost_multiprecision.ref.number.h4"></a>
  650. <span class="phrase"><a name="boost_multiprecision.ref.number.iostream_support"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.iostream_support">Iostream
  651. Support</a>
  652. </h5>
  653. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  654. <span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">&lt;&lt;</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="identifier">os</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  655. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Unspecified</span><span class="special">...&gt;</span>
  656. <span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">&lt;&lt;</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span><span class="special">&amp;</span> <span class="identifier">os</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">unmentionable</span><span class="special">-</span><span class="identifier">expression</span><span class="special">-</span><span class="keyword">template</span><span class="special">&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  657. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  658. <span class="keyword">inline</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">&gt;&gt;</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span><span class="special">&amp;</span> <span class="identifier">is</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">r</span><span class="special">)</span>
  659. </pre>
  660. <p>
  661. These operators provided formatted input-output operations on <code class="computeroutput"><span class="identifier">number</span></code> types, and expression templates
  662. derived from them.
  663. </p>
  664. <p>
  665. It's down to the back-end type to actually implement string conversion. However,
  666. the back-ends provided with this library support all of the iostream formatting
  667. flags, field width and precision settings.
  668. </p>
  669. <h5>
  670. <a name="boost_multiprecision.ref.number.h5"></a>
  671. <span class="phrase"><a name="boost_multiprecision.ref.number.arithmetic_with_a_higher_precisi"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.arithmetic_with_a_higher_precisi">Arithmetic
  672. with a higher precision result</a>
  673. </h5>
  674. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ResultType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Source1</span> <span class="keyword">class</span> <span class="identifier">Source2</span><span class="special">&gt;</span>
  675. <span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">add</span><span class="special">(</span><span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">result</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source1</span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source2</span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  676. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ResultType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Source1</span> <span class="keyword">class</span> <span class="identifier">Source2</span><span class="special">&gt;</span>
  677. <span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">subtract</span><span class="special">(</span><span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">result</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source1</span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source2</span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  678. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">ResultType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Source1</span> <span class="keyword">class</span> <span class="identifier">Source2</span><span class="special">&gt;</span>
  679. <span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">multiply</span><span class="special">(</span><span class="identifier">ResultType</span><span class="special">&amp;</span> <span class="identifier">result</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source1</span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">Source2</span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  680. </pre>
  681. <p>
  682. These functions apply the named operator to the arguments <span class="emphasis"><em>a</em></span>
  683. and <span class="emphasis"><em>b</em></span> and store the result in <span class="emphasis"><em>result</em></span>,
  684. returning <span class="emphasis"><em>result</em></span>. In all cases they behave "as
  685. if" arguments <span class="emphasis"><em>a</em></span> and <span class="emphasis"><em>b</em></span> were
  686. first promoted to type <code class="computeroutput"><span class="identifier">ResultType</span></code>
  687. before applying the operator, though particular backends may well avoid that
  688. step by way of an optimization.
  689. </p>
  690. <p>
  691. The type <code class="computeroutput"><span class="identifier">ResultType</span></code> must
  692. be an instance of class <code class="computeroutput"><span class="identifier">number</span></code>,
  693. and the types <code class="computeroutput"><span class="identifier">Source1</span></code> and
  694. <code class="computeroutput"><span class="identifier">Source2</span></code> may be either instances
  695. of class <code class="computeroutput"><span class="identifier">number</span></code> or native
  696. integer types. The latter is an optimization that allows arithmetic to be
  697. performed on native integer types producing an extended precision result.
  698. </p>
  699. <h5>
  700. <a name="boost_multiprecision.ref.number.h6"></a>
  701. <span class="phrase"><a name="boost_multiprecision.ref.number.non_member_standard_library_func"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.non_member_standard_library_func">Non-member
  702. standard library function support</a>
  703. </h5>
  704. <pre class="programlisting"><span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">abs</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  705. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">acos</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  706. <span class="emphasis"><em>number</em></span> <span class="identifier">acosh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  707. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">asin</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  708. <span class="emphasis"><em>number</em></span> <span class="identifier">asinh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  709. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">atan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  710. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">atan2</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  711. <span class="emphasis"><em>number</em></span> <span class="identifier">atanh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  712. <span class="emphasis"><em>number</em></span> <span class="identifier">cbrt</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  713. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">ceil</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  714. <span class="emphasis"><em>number</em></span> <span class="identifier">copysign</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  715. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">cos</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  716. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">cosh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  717. <span class="emphasis"><em>number</em></span> <span class="identifier">erf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  718. <span class="emphasis"><em>number</em></span> <span class="identifier">erfc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  719. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">exp</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  720. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">exp2</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  721. <span class="emphasis"><em>number</em></span> <span class="identifier">expm1</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  722. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fabs</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  723. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fdim</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  724. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">floor</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  725. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fma</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  726. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fmin</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  727. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fmax</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  728. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">fmod</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  729. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">frexp</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">*);</span>
  730. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">hypot</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  731. <span class="emphasis"><em>integer-type</em></span> <span class="identifier">ilogb</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  732. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">ldexp</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">);</span>
  733. <span class="emphasis"><em>number</em></span> <span class="identifier">lgamma</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  734. <span class="keyword">long</span> <span class="keyword">long</span> <span class="identifier">llrint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  735. <span class="keyword">long</span> <span class="keyword">long</span> <span class="identifier">llround</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  736. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">log</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  737. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">log2</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  738. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">log10</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  739. <span class="emphasis"><em>number</em></span> <span class="identifier">log1p</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  740. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">logb</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  741. <span class="keyword">long</span> <span class="identifier">lrint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  742. <span class="keyword">long</span> <span class="identifier">lround</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  743. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">modf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  744. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">nearbyint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  745. <span class="emphasis"><em>number</em></span> <span class="identifier">nextafter</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  746. <span class="emphasis"><em>number</em></span> <span class="identifier">nexttoward</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  747. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">pow</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  748. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">remainder</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  749. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">remquo</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">*);</span>
  750. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">rint</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  751. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">round</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  752. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">scalbn</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">);</span>
  753. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">scalbln</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="emphasis"><em>integer-type</em></span><span class="special">);</span>
  754. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sin</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  755. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sinh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  756. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sqrt</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  757. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">tan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  758. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">tanh</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  759. <span class="emphasis"><em>number</em></span> <span class="identifier">tgamma</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  760. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">trunc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  761. <span class="keyword">int</span> <span class="identifier">fpclassify</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  762. <span class="keyword">bool</span> <span class="identifier">isfinite</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  763. <span class="keyword">bool</span> <span class="identifier">isinf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  764. <span class="keyword">bool</span> <span class="identifier">isnan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  765. <span class="keyword">bool</span> <span class="identifier">isnormal</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  766. <span class="keyword">int</span> <span class="identifier">signbit</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  767. <span class="keyword">bool</span> <span class="identifier">isgreater</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  768. <span class="keyword">bool</span> <span class="identifier">isgreaterequal</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  769. <span class="keyword">bool</span> <span class="identifier">isless</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  770. <span class="keyword">bool</span> <span class="identifier">islessequal</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  771. <span class="keyword">bool</span> <span class="identifier">islessgreater</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  772. <span class="keyword">bool</span> <span class="identifier">isunordered</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  773. </pre>
  774. <p>
  775. These functions all behave exactly as their standard library C++11 counterparts
  776. do: their argument is either an instance of <code class="computeroutput"><span class="identifier">number</span></code>
  777. or an expression template derived from it; If the argument is of type <code class="computeroutput"><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">et_off</span><span class="special">&gt;</span></code>
  778. then that is also the return type, otherwise the return type is an expression
  779. template unless otherwise stated.
  780. </p>
  781. <p>
  782. The integer type arguments to <code class="computeroutput"><span class="identifier">ldexp</span></code>,
  783. <code class="computeroutput"><span class="identifier">frexp</span></code>, <code class="computeroutput"><span class="identifier">scalbn</span></code>
  784. and <code class="computeroutput"><span class="identifier">ilogb</span></code> may be either type
  785. <code class="computeroutput"><span class="keyword">int</span></code>, or the actual type of the
  786. exponent of the number type.
  787. </p>
  788. <p>
  789. Complex number types support the following functions:
  790. </p>
  791. <pre class="programlisting"><span class="comment">// Complex number functions:</span>
  792. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">real</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  793. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">imag</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  794. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">abs</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  795. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">arg</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  796. <span class="emphasis"><em>number&lt;...&gt;::value_type</em></span> <span class="identifier">norm</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  797. <span class="emphasis"><em>number</em></span> <span class="identifier">conj</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  798. <span class="emphasis"><em>number</em></span> <span class="identifier">proj</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  799. <span class="emphasis"><em>number</em></span> <span class="identifier">polar</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  800. </pre>
  801. <p>
  802. In addition the functions <code class="computeroutput"><span class="identifier">real</span></code>,
  803. <code class="computeroutput"><span class="identifier">imag</span></code>, <code class="computeroutput"><span class="identifier">arg</span></code>,
  804. <code class="computeroutput"><span class="identifier">norm</span></code>, <code class="computeroutput"><span class="identifier">conj</span></code>
  805. and <code class="computeroutput"><span class="identifier">proj</span></code> are overloaded for
  806. scalar (ie non-complex) types in the same manner as <code class="computeroutput"><span class="special">&lt;</span><span class="identifier">complex</span><span class="special">&gt;</span></code>
  807. and treat the argument as a value whose imaginary part is zero.
  808. </p>
  809. <p>
  810. There are also some functions implemented for compatibility with the Boost.Math
  811. functions of the same name:
  812. </p>
  813. <pre class="programlisting"><span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">itrunc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  814. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">ltrunc</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  815. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">lltrunc</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  816. <span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">iround</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  817. <span class="emphasis"><em>number</em></span> <span class="identifier">changesign</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  818. <span class="emphasis"><em>number</em></span> <span class="identifier">copysign</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  819. </pre>
  820. <p>
  821. All these functions are normally implemented by the Backend type. However,
  822. default versions are provided for Backend types that don't have native support
  823. for these functions. Please note however, that this default support requires
  824. the precision of the type to be a compile time constant - this means for
  825. example that the <a href="http://gmplib.org" target="_top">GMP</a> MPF Backend will
  826. not work with these functions when that type is used at variable precision.
  827. </p>
  828. <p>
  829. Also note that with the exception of <code class="computeroutput"><span class="identifier">abs</span></code>
  830. that these functions can only be used with floating-point Backend types (if
  831. any other types such as fixed precision or complex types are added to the
  832. library later, then these functions may be extended to support those number
  833. types).
  834. </p>
  835. <p>
  836. The precision of these functions is generally determined by the backend implementation.
  837. For example the precision of these functions when used with <a class="link" href="../tut/floats/mpfr_float.html" title="mpfr_float">mpfr_float</a>
  838. is determined entirely by <a href="http://www.mpfr.org" target="_top">MPFR</a>.
  839. When these functions use our own implementations, the accuracy of the transcendental
  840. functions is generally a few epsilon. Note however, that the trigonometrical
  841. functions incur the usual accuracy loss when reducing arguments by large
  842. multiples of &#960;. Also note that both <a class="link" href="../tut/floats/gmp_float.html" title="gmp_float">gmp_float</a>
  843. and <a class="link" href="../tut/floats/cpp_dec_float.html" title="cpp_dec_float">cpp_dec_float</a>
  844. have a number of guard digits beyond their stated precision, so the error
  845. rates listed for these are in some sense artificially low.
  846. </p>
  847. <p>
  848. The following table shows the error rates we observe for these functions
  849. with various backend types, functions not listed here are exact (tested on
  850. Win32 with VC++10, MPFR-3.0.0, MPIR-2.1.1):
  851. </p>
  852. <div class="informaltable"><table class="table">
  853. <colgroup>
  854. <col>
  855. <col>
  856. <col>
  857. <col>
  858. </colgroup>
  859. <thead><tr>
  860. <th>
  861. <p>
  862. Function
  863. </p>
  864. </th>
  865. <th>
  866. <p>
  867. mpfr_float_50
  868. </p>
  869. </th>
  870. <th>
  871. <p>
  872. mpf_float_50
  873. </p>
  874. </th>
  875. <th>
  876. <p>
  877. cpp_dec_float_50
  878. </p>
  879. </th>
  880. </tr></thead>
  881. <tbody>
  882. <tr>
  883. <td>
  884. <p>
  885. sqrt
  886. </p>
  887. </td>
  888. <td>
  889. <p>
  890. 1eps
  891. </p>
  892. </td>
  893. <td>
  894. <p>
  895. 0eps
  896. </p>
  897. </td>
  898. <td>
  899. <p>
  900. 0eps
  901. </p>
  902. </td>
  903. </tr>
  904. <tr>
  905. <td>
  906. <p>
  907. exp
  908. </p>
  909. </td>
  910. <td>
  911. <p>
  912. 1eps
  913. </p>
  914. </td>
  915. <td>
  916. <p>
  917. 0eps
  918. </p>
  919. </td>
  920. <td>
  921. <p>
  922. 0eps
  923. </p>
  924. </td>
  925. </tr>
  926. <tr>
  927. <td>
  928. <p>
  929. log
  930. </p>
  931. </td>
  932. <td>
  933. <p>
  934. 1eps
  935. </p>
  936. </td>
  937. <td>
  938. <p>
  939. 0eps
  940. </p>
  941. </td>
  942. <td>
  943. <p>
  944. 0eps
  945. </p>
  946. </td>
  947. </tr>
  948. <tr>
  949. <td>
  950. <p>
  951. log10
  952. </p>
  953. </td>
  954. <td>
  955. <p>
  956. 1eps
  957. </p>
  958. </td>
  959. <td>
  960. <p>
  961. 0eps
  962. </p>
  963. </td>
  964. <td>
  965. <p>
  966. 0eps
  967. </p>
  968. </td>
  969. </tr>
  970. <tr>
  971. <td>
  972. <p>
  973. cos
  974. </p>
  975. </td>
  976. <td>
  977. <p>
  978. 700eps
  979. </p>
  980. </td>
  981. <td>
  982. <p>
  983. 0eps
  984. </p>
  985. </td>
  986. <td>
  987. <p>
  988. 0eps
  989. </p>
  990. </td>
  991. </tr>
  992. <tr>
  993. <td>
  994. <p>
  995. sin
  996. </p>
  997. </td>
  998. <td>
  999. <p>
  1000. 1eps
  1001. </p>
  1002. </td>
  1003. <td>
  1004. <p>
  1005. 0eps
  1006. </p>
  1007. </td>
  1008. <td>
  1009. <p>
  1010. 0eps
  1011. </p>
  1012. </td>
  1013. </tr>
  1014. <tr>
  1015. <td>
  1016. <p>
  1017. tan
  1018. </p>
  1019. </td>
  1020. <td>
  1021. <p>
  1022. 0eps
  1023. </p>
  1024. </td>
  1025. <td>
  1026. <p>
  1027. 0eps
  1028. </p>
  1029. </td>
  1030. <td>
  1031. <p>
  1032. 0eps
  1033. </p>
  1034. </td>
  1035. </tr>
  1036. <tr>
  1037. <td>
  1038. <p>
  1039. acos
  1040. </p>
  1041. </td>
  1042. <td>
  1043. <p>
  1044. 0eps
  1045. </p>
  1046. </td>
  1047. <td>
  1048. <p>
  1049. 0eps
  1050. </p>
  1051. </td>
  1052. <td>
  1053. <p>
  1054. 0eps
  1055. </p>
  1056. </td>
  1057. </tr>
  1058. <tr>
  1059. <td>
  1060. <p>
  1061. asin
  1062. </p>
  1063. </td>
  1064. <td>
  1065. <p>
  1066. 0eps
  1067. </p>
  1068. </td>
  1069. <td>
  1070. <p>
  1071. 0eps
  1072. </p>
  1073. </td>
  1074. <td>
  1075. <p>
  1076. 0eps
  1077. </p>
  1078. </td>
  1079. </tr>
  1080. <tr>
  1081. <td>
  1082. <p>
  1083. atan
  1084. </p>
  1085. </td>
  1086. <td>
  1087. <p>
  1088. 1eps
  1089. </p>
  1090. </td>
  1091. <td>
  1092. <p>
  1093. 0eps
  1094. </p>
  1095. </td>
  1096. <td>
  1097. <p>
  1098. 0eps
  1099. </p>
  1100. </td>
  1101. </tr>
  1102. <tr>
  1103. <td>
  1104. <p>
  1105. cosh
  1106. </p>
  1107. </td>
  1108. <td>
  1109. <p>
  1110. 1045eps<a href="#ftn.boost_multiprecision.ref.number.f0" class="footnote" name="boost_multiprecision.ref.number.f0"><sup class="footnote">[1]</sup></a>
  1111. </p>
  1112. </td>
  1113. <td>
  1114. <p>
  1115. 0eps
  1116. </p>
  1117. </td>
  1118. <td>
  1119. <p>
  1120. 0eps
  1121. </p>
  1122. </td>
  1123. </tr>
  1124. <tr>
  1125. <td>
  1126. <p>
  1127. sinh
  1128. </p>
  1129. </td>
  1130. <td>
  1131. <p>
  1132. 2eps
  1133. </p>
  1134. </td>
  1135. <td>
  1136. <p>
  1137. 0eps
  1138. </p>
  1139. </td>
  1140. <td>
  1141. <p>
  1142. 0eps
  1143. </p>
  1144. </td>
  1145. </tr>
  1146. <tr>
  1147. <td>
  1148. <p>
  1149. tanh
  1150. </p>
  1151. </td>
  1152. <td>
  1153. <p>
  1154. 1eps
  1155. </p>
  1156. </td>
  1157. <td>
  1158. <p>
  1159. 0eps
  1160. </p>
  1161. </td>
  1162. <td>
  1163. <p>
  1164. 0eps
  1165. </p>
  1166. </td>
  1167. </tr>
  1168. <tr>
  1169. <td>
  1170. <p>
  1171. pow
  1172. </p>
  1173. </td>
  1174. <td>
  1175. <p>
  1176. 0eps
  1177. </p>
  1178. </td>
  1179. <td>
  1180. <p>
  1181. 4eps
  1182. </p>
  1183. </td>
  1184. <td>
  1185. <p>
  1186. 3eps
  1187. </p>
  1188. </td>
  1189. </tr>
  1190. <tr>
  1191. <td>
  1192. <p>
  1193. atan2
  1194. </p>
  1195. </td>
  1196. <td>
  1197. <p>
  1198. 1eps
  1199. </p>
  1200. </td>
  1201. <td>
  1202. <p>
  1203. 0eps
  1204. </p>
  1205. </td>
  1206. <td>
  1207. <p>
  1208. 0eps
  1209. </p>
  1210. </td>
  1211. </tr>
  1212. </tbody>
  1213. <tbody class="footnotes"><tr><td colspan="4"><div id="ftn.boost_multiprecision.ref.number.f0" class="footnote"><p><a href="#boost_multiprecision.ref.number.f0" class="para"><sup class="para">[1] </sup></a>
  1214. It's likely that the inherent error in the input values to our
  1215. test cases are to blame here.
  1216. </p></div></td></tr></tbody>
  1217. </table></div>
  1218. <h5>
  1219. <a name="boost_multiprecision.ref.number.h7"></a>
  1220. <span class="phrase"><a name="boost_multiprecision.ref.number.traits_class_support"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.traits_class_support">Traits Class
  1221. Support</a>
  1222. </h5>
  1223. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  1224. <span class="keyword">struct</span> <span class="identifier">component_type</span><span class="special">;</span>
  1225. </pre>
  1226. <p>
  1227. If this is a type with multiple components (for example rational or complex
  1228. types), then this trait has a single member <code class="computeroutput"><span class="identifier">type</span></code>
  1229. that is the type of those components.
  1230. </p>
  1231. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  1232. <span class="keyword">struct</span> <span class="identifier">number_category</span><span class="special">;</span>
  1233. </pre>
  1234. <p>
  1235. A traits class that inherits from <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">int_</span><span class="special">&lt;</span><span class="identifier">N</span><span class="special">&gt;</span></code>
  1236. where <code class="computeroutput"><span class="identifier">N</span></code> is one of the enumerated
  1237. values <code class="computeroutput"><span class="identifier">number_kind_integer</span></code>,
  1238. <code class="computeroutput"><span class="identifier">number_kind_floating_point</span></code>,
  1239. <code class="computeroutput"><span class="identifier">number_kind_rational</span></code>, <code class="computeroutput"><span class="identifier">number_kind_fixed_point</span></code>, or <code class="computeroutput"><span class="identifier">number_kind_unknown</span></code>. This traits class
  1240. is specialized for any type that has <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>
  1241. support as well as for classes in this library: which means it can be used
  1242. for generic code that must work with built in arithmetic types as well as
  1243. multiprecision ones.
  1244. </p>
  1245. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  1246. <span class="keyword">struct</span> <span class="identifier">is_number</span><span class="special">;</span>
  1247. </pre>
  1248. <p>
  1249. A traits class that inherits from <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code>
  1250. if T is an instance of <code class="computeroutput"><span class="identifier">number</span><span class="special">&lt;&gt;</span></code>, otherwise from <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">false_</span></code>.
  1251. </p>
  1252. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
  1253. <span class="keyword">struct</span> <span class="identifier">is_number_expression</span><span class="special">;</span>
  1254. </pre>
  1255. <p>
  1256. A traits class that inherits from <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code>
  1257. if T is an expression template type derived from <code class="computeroutput"><span class="identifier">number</span><span class="special">&lt;&gt;</span></code>, otherwise from <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">false_</span></code>.
  1258. </p>
  1259. <h5>
  1260. <a name="boost_multiprecision.ref.number.h8"></a>
  1261. <span class="phrase"><a name="boost_multiprecision.ref.number.integer_functions"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.integer_functions">Integer
  1262. functions</a>
  1263. </h5>
  1264. <p>
  1265. In addition to functioning with types from this library, these functions
  1266. are also overloaded for built in integer types if you include <code class="computeroutput"><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">multiprecision</span><span class="special">/</span><span class="identifier">integer</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>.
  1267. Further, when used with fixed precision types (whether built in integers
  1268. or multiprecision ones), the functions will promote to a wider type internally
  1269. when the algorithm requires it. Versions overloaded for built in integer
  1270. types return that integer type rather than an expression template.
  1271. </p>
  1272. <pre class="programlisting"><span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">gcd</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  1273. </pre>
  1274. <p>
  1275. Returns the largest integer <code class="computeroutput"><span class="identifier">x</span></code>
  1276. that divides both <code class="computeroutput"><span class="identifier">a</span></code> and
  1277. <code class="computeroutput"><span class="identifier">b</span></code>.
  1278. </p>
  1279. <pre class="programlisting"><span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">lcm</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  1280. </pre>
  1281. <p>
  1282. Returns the smallest integer <code class="computeroutput"><span class="identifier">x</span></code>
  1283. that is divisible by both <code class="computeroutput"><span class="identifier">a</span></code>
  1284. and <code class="computeroutput"><span class="identifier">b</span></code>.
  1285. </p>
  1286. <pre class="programlisting"><span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">pow</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">p</span><span class="special">);</span>
  1287. </pre>
  1288. <p>
  1289. Returns <span class="emphasis"><em>b<sup>p</sup></em></span> as an expression template. Note that this
  1290. function should be used with extreme care as the result can grow so large
  1291. as to take "effectively forever" to compute, or else simply run
  1292. the host machine out of memory. This is the one function in this category
  1293. that is not overloaded for built in integer types, further, it's probably
  1294. not a good idea to use it with fixed precision <code class="computeroutput"><span class="identifier">cpp_int</span></code>'s
  1295. either.
  1296. </p>
  1297. <pre class="programlisting"><span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">powm</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">b</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">p</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">m</span><span class="special">);</span>
  1298. </pre>
  1299. <p>
  1300. Returns <span class="emphasis"><em>b<sup>p</sup> mod m</em></span> as an expression template. Fixed precision
  1301. types are promoted internally to ensure accuracy.
  1302. </p>
  1303. <pre class="programlisting"><span class="emphasis"><em>unmentionable-expression-template-type</em></span> <span class="identifier">sqrt</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">);</span>
  1304. </pre>
  1305. <p>
  1306. Returns the largest integer <code class="computeroutput"><span class="identifier">x</span></code>
  1307. such that <code class="computeroutput"><span class="identifier">x</span> <span class="special">*</span>
  1308. <span class="identifier">x</span> <span class="special">&lt;</span>
  1309. <span class="identifier">a</span></code>.
  1310. </p>
  1311. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  1312. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">EXpressionTemplates</span><span class="special">&gt;</span> <span class="identifier">sqrt</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">EXpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  1313. </pre>
  1314. <p>
  1315. Returns the largest integer <code class="computeroutput"><span class="identifier">x</span></code>
  1316. such that <code class="computeroutput"><span class="identifier">x</span> <span class="special">*</span>
  1317. <span class="identifier">x</span> <span class="special">&lt;</span>
  1318. <span class="identifier">a</span></code>, and sets the remainder <code class="computeroutput"><span class="identifier">r</span></code> such that <code class="computeroutput"><span class="identifier">r</span>
  1319. <span class="special">=</span> <span class="identifier">a</span> <span class="special">-</span> <span class="identifier">x</span> <span class="special">*</span>
  1320. <span class="identifier">x</span></code>.
  1321. </p>
  1322. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">expression_template_option</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  1323. <span class="keyword">void</span> <span class="identifier">divide_qr</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">y</span><span class="special">,</span>
  1324. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">q</span><span class="special">,</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">r</span><span class="special">);</span>
  1325. </pre>
  1326. <p>
  1327. Divides x by y and returns both the quotient and remainder. After the call
  1328. <code class="computeroutput"><span class="identifier">q</span> <span class="special">=</span>
  1329. <span class="identifier">x</span> <span class="special">/</span> <span class="identifier">y</span></code> and <code class="computeroutput"><span class="identifier">r</span>
  1330. <span class="special">=</span> <span class="identifier">x</span> <span class="special">%</span> <span class="identifier">y</span></code>.
  1331. </p>
  1332. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Integer</span><span class="special">&gt;</span>
  1333. <span class="identifier">Integer</span> <span class="identifier">integer_modulus</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">Integer</span> <span class="identifier">val</span><span class="special">);</span>
  1334. </pre>
  1335. <p>
  1336. Returns the absolute value of <code class="computeroutput"><span class="identifier">x</span>
  1337. <span class="special">%</span> <span class="identifier">val</span></code>.
  1338. </p>
  1339. <pre class="programlisting"><span class="keyword">unsigned</span> <span class="identifier">lsb</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">);</span>
  1340. </pre>
  1341. <p>
  1342. Returns the (zero-based) index of the least significant bit that is set to
  1343. 1.
  1344. </p>
  1345. <p>
  1346. Throws a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">range_error</span></code> if the argument is &lt;= 0.
  1347. </p>
  1348. <pre class="programlisting"><span class="keyword">unsigned</span> <span class="identifier">msb</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">);</span>
  1349. </pre>
  1350. <p>
  1351. Returns the (zero-based) index of the most significant bit.
  1352. </p>
  1353. <p>
  1354. Throws a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">range_error</span></code> if the argument is &lt;= 0.
  1355. </p>
  1356. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  1357. <span class="keyword">bool</span> <span class="identifier">bit_test</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  1358. </pre>
  1359. <p>
  1360. Returns <code class="computeroutput"><span class="keyword">true</span></code> if the bit at
  1361. <span class="emphasis"><em>index</em></span> in <span class="emphasis"><em>val</em></span> is set.
  1362. </p>
  1363. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  1364. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">bit_set</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  1365. </pre>
  1366. <p>
  1367. Sets the bit at <span class="emphasis"><em>index</em></span> in <span class="emphasis"><em>val</em></span>, and
  1368. returns <span class="emphasis"><em>val</em></span>.
  1369. </p>
  1370. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  1371. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">bit_unset</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  1372. </pre>
  1373. <p>
  1374. Unsets the bit at <span class="emphasis"><em>index</em></span> in <span class="emphasis"><em>val</em></span>,
  1375. and returns <span class="emphasis"><em>val</em></span>.
  1376. </p>
  1377. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  1378. <span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">bit_flip</span><span class="special">(</span><span class="identifier">number</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;&amp;</span> <span class="identifier">val</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">index</span><span class="special">);</span>
  1379. </pre>
  1380. <p>
  1381. Flips the bit at <span class="emphasis"><em>index</em></span> in <span class="emphasis"><em>val</em></span>,
  1382. and returns <span class="emphasis"><em>val</em></span>.
  1383. </p>
  1384. <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Engine</span><span class="special">&gt;</span>
  1385. <span class="keyword">bool</span> <span class="identifier">miller_rabin_test</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">n</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">trials</span><span class="special">,</span> <span class="identifier">Engine</span><span class="special">&amp;</span> <span class="identifier">gen</span><span class="special">);</span>
  1386. <span class="keyword">bool</span> <span class="identifier">miller_rabin_test</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;</span> <span class="identifier">n</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">trials</span><span class="special">);</span>
  1387. </pre>
  1388. <p>
  1389. Tests to see if the number <span class="emphasis"><em>n</em></span> is probably prime - the
  1390. test excludes the vast majority of composite numbers by excluding small prime
  1391. factors and performing a single Fermat test. Then performs <span class="emphasis"><em>trials</em></span>
  1392. Miller-Rabin tests. Returns <code class="computeroutput"><span class="keyword">false</span></code>
  1393. if <span class="emphasis"><em>n</em></span> is definitely composite, or <code class="computeroutput"><span class="keyword">true</span></code>
  1394. if <span class="emphasis"><em>n</em></span> is probably prime with the probability of it being
  1395. composite less than 0.25^trials. Fixed precision types are promoted internally
  1396. to ensure accuracy.
  1397. </p>
  1398. <h5>
  1399. <a name="boost_multiprecision.ref.number.h9"></a>
  1400. <span class="phrase"><a name="boost_multiprecision.ref.number.rational_number_functions"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.rational_number_functions">Rational
  1401. Number Functions</a>
  1402. </h5>
  1403. <pre class="programlisting"><span class="keyword">typename</span> <span class="identifier">component_type</span><span class="special">&lt;</span><span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">numerator</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  1404. <span class="keyword">typename</span> <span class="identifier">component_type</span><span class="special">&lt;</span><span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">denominator</span><span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;);</span>
  1405. </pre>
  1406. <p>
  1407. These functions return the numerator and denominator of a rational number
  1408. respectively.
  1409. </p>
  1410. <h5>
  1411. <a name="boost_multiprecision.ref.number.h10"></a>
  1412. <span class="phrase"><a name="boost_multiprecision.ref.number.boost_math_interoperability_supp"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.boost_math_interoperability_supp">Boost.Math
  1413. Interoperability Support</a>
  1414. </h5>
  1415. <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span><span class="special">{</span>
  1416. <span class="keyword">int</span> <span class="identifier">fpclassify</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  1417. <span class="keyword">bool</span> <span class="identifier">isfinite</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  1418. <span class="keyword">bool</span> <span class="identifier">isnan</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  1419. <span class="keyword">bool</span> <span class="identifier">isinf</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  1420. <span class="keyword">bool</span> <span class="identifier">isnormal</span> <span class="special">(</span><span class="keyword">const</span> <span class="emphasis"><em>number-or-expression-template-type</em></span><span class="special">&amp;,</span> <span class="keyword">int</span><span class="special">);</span>
  1421. <span class="special">}}</span> <span class="comment">// namespaces</span>
  1422. </pre>
  1423. <p>
  1424. These floating-point classification functions behave exactly as their Boost.Math
  1425. equivalents.
  1426. </p>
  1427. <p>
  1428. Other Boost.Math functions and templates may also be specialized or overloaded
  1429. to ensure interoperability.
  1430. </p>
  1431. <h5>
  1432. <a name="boost_multiprecision.ref.number.h11"></a>
  1433. <span class="phrase"><a name="boost_multiprecision.ref.number.std_numeric_limits_support"></a></span><a class="link" href="number.html#boost_multiprecision.ref.number.std_numeric_limits_support">std::numeric_limits
  1434. support</a>
  1435. </h5>
  1436. <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">std</span><span class="special">{</span>
  1437. <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span>
  1438. <span class="keyword">struct</span> <span class="identifier">numeric_limits</span><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">multiprecision</span><span class="special">&lt;</span><span class="identifier">Backend</span><span class="special">,</span> <span class="identifier">ExpressionTemplates</span><span class="special">&gt;</span> <span class="special">&gt;</span>
  1439. <span class="special">{</span>
  1440. <span class="comment">/* Usual members here */</span>
  1441. <span class="special">};</span>
  1442. <span class="special">}</span>
  1443. </pre>
  1444. <p>
  1445. Class template <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code> is specialized for all instantiations
  1446. of <code class="computeroutput"><span class="identifier">number</span></code> whose precision
  1447. is known at compile time, plus those types whose precision is unlimited (though
  1448. it is much less useful in those cases). It is not specialized for types whose
  1449. precision can vary at compile time (such as <code class="computeroutput"><span class="identifier">mpf_float</span></code>).
  1450. </p>
  1451. </div>
  1452. <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
  1453. <td align="left"></td>
  1454. <td align="right"><div class="copyright-footer">Copyright &#169; 2002-2019 John Maddock
  1455. and Christopher Kormanyos<p>
  1456. Distributed under the Boost Software License, Version 1.0. (See accompanying
  1457. file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
  1458. </p>
  1459. </div></td>
  1460. </tr></table>
  1461. <hr>
  1462. <div class="spirit-nav">
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