std::numeric_limits::has_quiet_NaN(3)

NAME
std::numeric_limits::has_quiet_NaN - std::numeric_limits::has_quiet_NaN

Synopsis
   static const bool has_quiet_NaN; (until C++11)
   static constexpr bool has_quiet_NaN; (since C++11)
   The value of std::numeric_limits<T>::has_quiet_NaN is true for all types T capable
   of representing the special value "Quiet Not-A-Number". This constant is meaningful
   for all floating-point types and is guaranteed to be true if
   std::numeric_limits<T>::is_iec559 == true.

Standard specializations
   T value of std::numeric_limits<T>::has_quiet_NaN
   /* 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
   quiet_NaN returns a quiet NaN value of the given floating-point type
   [static] (public static member function)
   has_infinity identifies floating-point types that can represent the special
   [static] value "positive infinity"
                     (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)