std::numeric_limits<T>::has_quiet_NaN

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`
signedchar	`false`
unsignedchar	`false`
wchar_t	`false`
char8_t (since C++20)	`false`
char16_t (since C++11)	`false`
char32_t (since C++11)	`false`
short	`false`
unsignedshort	`false`
int	`false`
unsignedint	`false`
long	`false`
unsignedlong	`false`
longlong (since C++11)	`false`
unsignedlonglong (since C++11)	`false`
float	usually `true`
double	usually `true`
longdouble	usually `true`

quiet_NaN [static]	returns a quiet NaN value of the given floating-point type (public static member function)
has_infinity [static]	identifies floating-point types that can represent the special value "positive infinity" (public static member constant)
has_signaling_NaN [static]	identifies floating-point types that can represent the special value "signaling not-a-number" (NaN) (public static member constant)

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std::numeric_limits<T>::has_quiet_NaN

Standard specializations

See also