| // Copyright John Maddock 2007. |
| // Copyright Paul A. Bristow 2010 |
| // 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) |
| |
| #include <iostream> |
| using std::cout; using std::endl; |
| #include <cerrno> // for ::errno |
| |
| //[policy_eg_2 |
| |
| #include <boost/math/special_functions/gamma.hpp> |
| using boost::math::tgamma; |
| |
| int main() |
| { |
| // using namespace boost::math::policies; // or |
| using boost::math::policies::errno_on_error; |
| using boost::math::policies::make_policy; |
| using boost::math::policies::pole_error; |
| using boost::math::policies::domain_error; |
| using boost::math::policies::overflow_error; |
| using boost::math::policies::evaluation_error; |
| |
| errno = 0; |
| std::cout << "Result of tgamma(30000) is: " |
| << boost::math::tgamma( |
| 30000, |
| make_policy( |
| domain_error<errno_on_error>(), |
| pole_error<errno_on_error>(), |
| overflow_error<errno_on_error>(), |
| evaluation_error<errno_on_error>() |
| ) |
| ) << std::endl; |
| // Check errno was set: |
| std::cout << "errno = " << errno << std::endl; |
| // and again with evaluation at a pole: |
| std::cout << "Result of tgamma(-10) is: " |
| << boost::math::tgamma( |
| -10, |
| make_policy( |
| domain_error<errno_on_error>(), |
| pole_error<errno_on_error>(), |
| overflow_error<errno_on_error>(), |
| evaluation_error<errno_on_error>() |
| ) |
| ) << std::endl; |
| // Check errno was set: |
| std::cout << "errno = " << errno << std::endl; |
| } |
| |
| //] //[/policy_eg_2] |
| |
| /* |
| |
| Output: |
| |
| Result of tgamma(30000) is: 1.#INF |
| errno = 34 |
| Result of tgamma(-10) is: 1.#QNAN |
| errno = 33 |
| */ |
| |