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- // Use, modification and distribution are subject to the
- // Boost Software License, Version 1.0. (See accompanying file
- // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- // Copyright Paul A. Bristow 2013
- // Copyright Christopher Kormanyos 2013.
- // Copyright John Maddock 2013.
- #ifdef _MSC_VER
- # pragma warning (disable : 4512)
- # pragma warning (disable : 4996)
- #endif
- #define BOOST_TEST_MAIN
- #define BOOST_LIB_DIAGNOSTIC "on"// Show library file details.
- #include <boost/test/unit_test.hpp>
- #include <boost/test/tools/floating_point_comparison.hpp> // Extra test tool for FP comparison.
- #include <iostream>
- #include <limits>
- //[expression_template_1
- #include <boost/multiprecision/cpp_dec_float.hpp>
- /*`To define a 50 decimal digit type using `cpp_dec_float`,
- you must pass two template parameters to `boost::multiprecision::number`.
- It may be more legible to use a two-staged type definition such as this:
- ``
- typedef boost::multiprecision::cpp_dec_float<50> mp_backend;
- typedef boost::multiprecision::number<mp_backend, boost::multiprecision::et_off> cpp_dec_float_50_noet;
- ``
- Here, we first define `mp_backend` as `cpp_dec_float` with 50 digits.
- The second step passes this backend to `boost::multiprecision::number`
- with `boost::multiprecision::et_off`, an enumerated type.
- typedef boost::multiprecision::number<boost::multiprecision::cpp_dec_float<50>, boost::multiprecision::et_off>
- cpp_dec_float_50_noet;
- You can reduce typing with a `using` directive `using namespace boost::multiprecision;`
- if desired, as shown below.
- */
- using namespace boost::multiprecision;
- /*`Now `cpp_dec_float_50_noet` or `cpp_dec_float_50_et`
- can be used as a direct replacement for built-in types like `double` etc.
- */
- BOOST_AUTO_TEST_CASE(cpp_float_test_check_close_noet)
- { // No expression templates/
- typedef number<cpp_dec_float<50>, et_off> cpp_dec_float_50_noet;
- std::cout.precision(std::numeric_limits<cpp_dec_float_50_noet>::digits10); // All significant digits.
- std::cout << std::showpoint << std::endl; // Show trailing zeros.
- cpp_dec_float_50_noet a ("1.0");
- cpp_dec_float_50_noet b ("1.0");
- b += std::numeric_limits<cpp_dec_float_50_noet>::epsilon(); // Increment least significant decimal digit.
- cpp_dec_float_50_noet eps = std::numeric_limits<cpp_dec_float_50_noet>::epsilon();
- std::cout <<"a = " << a << ",\nb = " << b << ",\neps = " << eps << std::endl;
- BOOST_CHECK_CLOSE(a, b, eps * 100); // Expected to pass (because tolerance is as percent).
- BOOST_CHECK_CLOSE_FRACTION(a, b, eps); // Expected to pass (because tolerance is as fraction).
- } // BOOST_AUTO_TEST_CASE(cpp_float_test_check_close)
- BOOST_AUTO_TEST_CASE(cpp_float_test_check_close_et)
- { // Using expression templates.
- typedef number<cpp_dec_float<50>, et_on> cpp_dec_float_50_et;
- std::cout.precision(std::numeric_limits<cpp_dec_float_50_et>::digits10); // All significant digits.
- std::cout << std::showpoint << std::endl; // Show trailing zeros.
- cpp_dec_float_50_et a("1.0");
- cpp_dec_float_50_et b("1.0");
- b += std::numeric_limits<cpp_dec_float_50_et>::epsilon(); // Increment least significant decimal digit.
- cpp_dec_float_50_et eps = std::numeric_limits<cpp_dec_float_50_et>::epsilon();
- std::cout << "a = " << a << ",\nb = " << b << ",\neps = " << eps << std::endl;
- BOOST_CHECK_CLOSE(a, b, eps * 100); // Expected to pass (because tolerance is as percent).
- BOOST_CHECK_CLOSE_FRACTION(a, b, eps); // Expected to pass (because tolerance is as fraction).
- /*`Using `cpp_dec_float_50` with the default expression template use switched on,
- the compiler error message for `BOOST_CHECK_CLOSE_FRACTION(a, b, eps); would be:
- */
- // failure floating_point_comparison.hpp(59): error C2440: 'static_cast' :
- // cannot convert from 'int' to 'boost::multiprecision::detail::expression<tag,Arg1,Arg2,Arg3,Arg4>'
- //] [/expression_template_1]
- } // BOOST_AUTO_TEST_CASE(cpp_float_test_check_close)
- /*
- Output:
- Description: Autorun "J:\Cpp\big_number\Debug\test_cpp_float_close_fraction.exe"
- Running 1 test case...
- a = 1.0000000000000000000000000000000000000000000000000,
- b = 1.0000000000000000000000000000000000000000000000001,
- eps = 1.0000000000000000000000000000000000000000000000000e-49
- *** No errors detected
- */
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