// (C) Copyright Matt Borland 2021. // 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) #ifndef BOOST_MATH_CCMATH_ISNAN #define BOOST_MATH_CCMATH_ISNAN #include <cmath> #include <type_traits> #include <boost/math/tools/is_constant_evaluated.hpp> namespace boost::math::ccmath { template <typename T> inline constexpr bool isnan(T x) { if(BOOST_MATH_IS_CONSTANT_EVALUATED(x)) { return x != x; } else { using std::isnan; if constexpr (!std::is_integral_v<T>) { return isnan(x); } else { return isnan(static_cast<double>(x)); } } } } #endif // BOOST_MATH_CCMATH_ISNAN