math/ccmath/isinf.hpp

0001 //  (C) Copyright Matt Borland 2021.
0002 //  Use, modification and distribution are subject to the
0003 //  Boost Software License, Version 1.0. (See accompanying file
0004 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005
0006 #ifndef BOOST_MATH_CCMATH_ISINF
0007 #define BOOST_MATH_CCMATH_ISINF
0008
0009 #include <boost/math/special_functions/fpclassify.hpp>
0010 #include <boost/math/ccmath/detail/config.hpp>
0011
0012 #ifdef BOOST_MATH_NO_CCMATH
0013 #error "The header <boost/math/isinf.hpp> can only be used in C++17 and later."
0014 #endif
0015
0016 namespace boost::math::ccmath {
0017
0018 template <typename T>
0019 constexpr bool isinf BOOST_MATH_PREVENT_MACRO_SUBSTITUTION(T x) noexcept
0020 {
0021     if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))
0022     {
0023         if constexpr (std::numeric_limits<T>::is_signed)
0024         {
0025 #if defined(__clang_major__) && __clang_major__ >= 6
0026 #  pragma clang diagnostic push
0027 #  pragma clang diagnostic ignored "-Wtautological-constant-compare"
0028 #  if defined(__has_warning)
0029 #    if __has_warning("-Wnan-infinity-disabled")
0030 #      pragma clang diagnostic ignored "-Wnan-infinity-disabled"
0031 #    endif
0032 #  endif
0033 #endif
0034             return x == std::numeric_limits<T>::infinity() || -x == std::numeric_limits<T>::infinity();
0035 #if defined(__clang_major__) && __clang_major__ >= 6
0036 #pragma clang diagnostic pop
0037 #endif
0038         }
0039         else
0040         {
0041             return x == std::numeric_limits<T>::infinity();
0042         }
0043     }
0044     else
0045     {
0046         using boost::math::isinf;
0047
0048         if constexpr (!std::is_integral_v<T>)
0049         {
0050             return (isinf)(x);
0051         }
0052         else
0053         {
0054             return (isinf)(static_cast<double>(x));
0055         }
0056     }
0057 }
0058
0059 }
0060
0061 #endif // BOOST_MATH_CCMATH_ISINF