std::numeric_limits::is_iec559(3)

NAME
std::numeric_limits::is_iec559 - std::numeric_limits::is_iec559

Synopsis
   static const bool is_iec559; (until C++11)
   static constexpr bool is_iec559; (since C++11)
   The value of std::numeric_limits<T>::is_iec559 is true for all floating-point types
   T which fulfill the requirements of IEC 559 (IEEE 754) standard. If
   std::numeric_limits<T>::is_iec559 is true, then
   std::numeric_limits<T>::has_infinity, std::numeric_limits<T>::has_quiet_NaN, and
   std::numeric_limits<T>::has_signaling_NaN are also true.

Standard specializations
   T value of std::numeric_limits<T>::is_iec559
   /* non-specialized */ false
   bool false
   char false
   signed char false
   unsigned char false
   wchar_t false
   char8_t (C++20) false
   char16_t (C++11) false
   char32_t (C++11) false
   short false
   unsigned short false
   int false
   unsigned int false
   long false
   unsigned long false
   long long (C++11) false
   unsigned long long (C++11) false
   float usually true
   double usually true
   long double usually true

See also
   has_infinity identifies floating-point types that can represent the special
   [static] value "positive infinity"
                     (public static member constant)
   has_quiet_NaN identifies floating-point types that can represent the special
   [static] value "quiet not-a-number" (NaN)
                     (public static member constant)
   has_signaling_NaN identifies floating-point types that can represent the special
   [static] value "signaling not-a-number" (NaN)
                     (public static member constant)