std::numeric_limits<T>::is_exact

 

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numeric_limits
C numeric limits interface
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type_info type_index (C++11)	bad_typeid bad_cast

 

std::numeric_limits

Static constants

numeric_limits::is_specialized

numeric_limits::is_signed

numeric_limits::is_integer

numeric_limits::is_exact

numeric_limits::has_infinity

numeric_limits::has_quiet_NaN

numeric_limits::has_signaling_NaN

numeric_limits::has_denorm

numeric_limits::has_denorm_loss

numeric_limits::round_style

numeric_limits::is_iec559

numeric_limits::is_bounded

numeric_limits::is_modulo

numeric_limits::digits

numeric_limits::digits10

numeric_limits::max_digits10 (C++11)

numeric_limits::radix

numeric_limits::min_exponent

numeric_limits::min_exponent10

numeric_limits::max_exponent

numeric_limits::max_exponent10

numeric_limits::traps

numeric_limits::tinyness_before

Static member functions

numeric_limits::min

numeric_limits::lowest (C++11)

numeric_limits::max

numeric_limits::epsilon

numeric_limits::round_error

numeric_limits::infinity

numeric_limits::quiet_NaN

numeric_limits::signaling_NaN

numeric_limits::denorm_min

Helper types

float_round_style

float_denorm_style

 

staticconstbool is_exact;		(until C++11)
staticconstexprbool 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
signedchar	true
unsignedchar	true
wchar_t	true
char8_t(since C++20)	true
char16_t(since C++11)	true
char32_t(since C++11)	true
short	true
unsignedshort	true
int	true
unsignedint	true
long	true
unsignedlong	true
longlong(since C++11)	true
unsignedlonglong(since C++11)	true
float	false
double	false
longdouble	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)