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Showing content from https://en.cppreference.com/w/cpp/language/../keywords/../types/numeric_limits/is_modulo.html below:

std::numeric_limits<T>::is_modulo - cppreference.com

static const bool is_modulo;

(until C++11)

static constexpr bool is_modulo;

(since C++11)

The value of std::numeric_limits<T>::is_modulo is true for all arithmetic types T that handle overflows with modulo arithmetic, that is, if the result of addition, subtraction, multiplication, or division of this type would fall outside the range [min(), max()], the value returned by such operation differs from the expected value by a multiple of max() - min() + 1.

is_modulo is false for signed integer types, unless the implementation defines signed integer overflow to wrap.

[edit] Standard specializations T value of std::numeric_limits<T>::is_modulo /* non-specialized */ false bool false char implementation-defined signed char implementation-defined unsigned char true wchar_t implementation-defined char8_t (since C++20) true char16_t (since C++11) true char32_t (since C++11) true short implementation-defined unsigned short true int implementation-defined unsigned int true long implementation-defined unsigned long true long long (C++11) implementation-defined unsigned long long (C++11) true float false double false long double false [edit] Notes

The standard said "On most machines, this is true for signed integers." before the resolution of LWG issue 2422. See GCC PR 22200 for a related discussion.

[edit] Example

Demonstrates the behavior of modulo types:

Possible output:

max value is 2147483647
min value is -2147483648
max value + 1 is -2147483648
 
max value is 18446744073709551615
min value is 0
max value + 1 is 0
[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior LWG 612 C++98 the definition of "handle overflows
with modulo arithmetic" was poor[1] provided a
better definition LWG 2422 C++98 is_modulo was required to be true for
signed integer types on most machines required to be false for signed integer types
unless signed integer overflow is defined to wrap
  1. ↑ The definition is "adding two positive numbers can have a result that wraps around to a third number that is less". It has the following problems:
    • It does not define the wrapped value.
    • It does not state whether result is repeatable.
    • It does not require that doing addition, subtraction and other operations on all values have defined behavior.
[edit] See also identifies integer types
(public static member constant) [edit] identifies the IEC 559/IEEE 754 floating-point types
(public static member constant) [edit] identifies exact types
(public static member constant) [edit]

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