Type support
Basic types
Fundamental types
Fixed width integer types (C++11)
Numeric limits
C numeric limits interface
Runtime type information
Type traits
Type categories
Type properties
(C++11)(until C++20)
(C++11)(deprecated in C++20)
Type trait constants
Constant evaluation context
Supported operations
Relationships and property queries
Type modifications
Type transformations
(C++11)(until C++20)(C++17)
static T round_error() throw();
(until C++11)
static constexpr T round_error() noexcept;
(since C++11)

Returns the largest possible rounding error in ULPs (units in the last place) as defined by ISO 10967, which can vary from 0.5 (rounding to the nearest digit) to 1.0 (rounding to zero or to infinity). It is only meaningful if std::numeric_limits<T>::is_integer == false.

Return value

T std::numeric_limits<T>::round_error()
/* non-specialized */ T()
bool false
char 0
signed char 0
unsigned char 0
wchar_t 0
char8_t 0
char16_t 0
char32_t 0
short 0
unsigned short 0
int 0
unsigned int 0
long 0
unsigned long 0
long long 0
unsigned long long 0
float 0.5F
double 0.5
long double 0.5L

See also

identifies the rounding style used by the type
(public static member constant)