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- // rational number example program ----------------------------------------//
- // (C) Copyright Paul Moore 1999. Permission to copy, use, modify, sell
- // and distribute this software is granted provided this copyright notice
- // appears in all copies. This software is provided "as is" without express or
- // implied warranty, and with no claim as to its suitability for any purpose.
- // boostinspect:nolicense (don't complain about the lack of a Boost license)
- // (Paul Moore hasn't been in contact for years, so there's no way to change the
- // license.)
- // Revision History
- // 14 Dec 99 Initial version
- #include <iostream>
- #include <cassert>
- #include <cstdlib>
- #include <boost/config.hpp>
- #ifndef BOOST_NO_LIMITS
- #include <limits>
- #else
- #include <limits.h>
- #endif
- #include <exception>
- #include <boost/rational.hpp>
- using std::cout;
- using std::endl;
- using boost::rational;
- #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
- // This is a nasty hack, required because MSVC does not implement "Koenig
- // Lookup". Basically, if I call abs(r), the C++ standard says that the
- // compiler should look for a definition of abs in the namespace which
- // contains r's class (in this case boost) - among other places.
- // Koenig Lookup is a relatively recent feature, and other compilers may not
- // implement it yet. If so, try including this line.
- using boost::abs;
- #endif
- int main ()
- {
- rational<int> half(1,2);
- rational<int> one(1);
- rational<int> two(2);
- // Some basic checks
- assert(half.numerator() == 1);
- assert(half.denominator() == 2);
- assert(boost::rational_cast<double>(half) == 0.5);
- // Arithmetic
- assert(half + half == one);
- assert(one - half == half);
- assert(two * half == one);
- assert(one / half == two);
- // With conversions to integer
- assert(half+half == 1);
- assert(2 * half == one);
- assert(2 * half == 1);
- assert(one / half == 2);
- assert(1 / half == 2);
- // Sign handling
- rational<int> minus_half(-1,2);
- assert(-half == minus_half);
- assert(abs(minus_half) == half);
- // Do we avoid overflow?
- #ifndef BOOST_NO_LIMITS
- int maxint = (std::numeric_limits<int>::max)();
- #else
- int maxint = INT_MAX;
- #endif
- rational<int> big(maxint, 2);
- assert(2 * big == maxint);
- // Print some of the above results
- cout << half << "+" << half << "=" << one << endl;
- cout << one << "-" << half << "=" << half << endl;
- cout << two << "*" << half << "=" << one << endl;
- cout << one << "/" << half << "=" << two << endl;
- cout << "abs(" << minus_half << ")=" << half << endl;
- cout << "2 * " << big << "=" << maxint
- << " (rational: " << rational<int>(maxint) << ")" << endl;
- // Some extras
- rational<int> pi(22,7);
- cout << "pi = " << boost::rational_cast<double>(pi) << " (nearly)" << endl;
- // Exception handling
- try {
- rational<int> r; // Forgot to initialise - set to 0
- r = 1/r; // Boom!
- }
- catch (const boost::bad_rational &e) {
- cout << "Bad rational, as expected: " << e.what() << endl;
- }
- catch (...) {
- cout << "Wrong exception raised!" << endl;
- }
- return 0;
- }
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