std::numeric_limits<T>::is_exact

 

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C numeric limits interface
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std::numeric_limits

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numeric_limits::is_specialized

numeric_limits::is_signed

numeric_limits::is_integer

numeric_limits::is_exact

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numeric_limits::has_signaling_NaN

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numeric_limits::max_exponent10

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numeric_limits::min

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numeric_limits::round_error

numeric_limits::infinity

numeric_limits::quiet_NaN

numeric_limits::signaling_NaN

numeric_limits::denorm_min

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float_denorm_style

 

static const bool is_exact;		(until C++11)
static constexpr bool is_exact;		(since C++11)

The value of std::numeric_limits<T>::is_exact is true for all arithmetic types T that use exact representation.

Standard specializations

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

Notes

While all fundamental types T for which std::numeric_limits<T>::is_exact == true are integer types, a library may define exact types that are not integers, e.g. a rational arithmetic type representing fractions.

See also

is_integer [static]	identifies integer types (public static member constant)
is_signed [static]	identifies signed types (public static member constant)
is_bounded [static]	identifies types that represent a finite set of values (public static member constant)