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

The value of std::numeric_limits<T>::traps is true for all arithmetic types T that have at least one value that, if used as an argument to an arithmetic operation, will generate a trap.

Standard specializations

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


On most platforms integer division by zero always traps, and std::numeric_limits<T>::traps is true for all integer types that support the value 0. The exception is the type bool: even though division by false traps due to integral promotion from bool to int, it is the zero-valued int that traps. Zero is not a value of type bool.

On most platforms, floating-point exceptions may be turned on and off at run time (e.g. feenableexcept() on Linux or _controlfp on Windows), in which case the value of std::numeric_limits<T>::traps for floating-point types reflects the state of floating-point trapping facility at the time of program startup, which is false on most modern systems. An exception would be a DEC Alpha program, where it is true if compiled without -ieee.

See also

Floating-point environment
identifies floating-point types that detect tinyness before rounding
(public static member constant)
identifies the floating-point types that detect loss of precision as denormalization loss rather than inexact result
(public static member constant)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.