policy_eg_2.cpp

来自「Boost provides free peer-reviewed portab」· C++ 代码 · 共 45 行

//  Copyright John Maddock 2007.
//  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>

//[policy_eg_2

#include <boost/math/special_functions/gamma.hpp>

int main()
{
   using namespace boost::math::policies;
   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;
}

//]