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// 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)
// Note that this file contains quickbook mark-up as well as code
// and comments, don't change any of the special comment mark-ups!
#include <iostream>
using std::cout; using std::endl;
#include <cerrno> // for ::errno
//[policy_eg_5
#include <boost/math/special_functions.hpp>
// using boost::math::tgamma; // Would create an ambiguity between
// 'double boost::math::tgamma<int>(T)' and
// 'double 'anonymous-namespace'::tgamma<int>(RT)'.
namespace mymath
{ // unnamed
using namespace boost::math::policies;
typedef policy<
domain_error<errno_on_error>,
pole_error<errno_on_error>,
overflow_error<errno_on_error>,
evaluation_error<errno_on_error>
> c_policy;
BOOST_MATH_DECLARE_SPECIAL_FUNCTIONS(c_policy)
/*`
So that when we call `mymath::tgamma(z)`, we really end up calling
`boost::math::tgamma(z, anonymous-namespace::c_policy())`.
*/
} // close unnamed namespace
int main()
{
errno = 0;
cout << "Result of tgamma(30000) is: "
<< mymath::tgamma(30000) << endl;
// tgamma in unnamed namespace in this translation unit (file) only.
cout << "errno = " << errno << endl;
cout << "Result of tgamma(-10) is: "
<< mymath::tgamma(-10) << endl;
cout << "errno = " << errno << endl;
// Default tgamma policy would throw an exception, and abort.
}
//] //[/policy_eg_5]
/*
Output:
Result of tgamma(30000) is: 1.#INF
errno = 34
Result of tgamma(-10) is: 1.#QNAN
errno = 33
*/
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