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Showing content from https://en.cppreference.com/w/cpp/language/../iterator/is-integer-like.html below:

is-integer-likeâï»¿, is-signed-integer-like - cppreference.com

template< class T > constexpr bool /*is-integer-like*/ = /* see description */;

(1) (since C++20)
(exposition only*)

template< class T > constexpr bool /*is-signed-integer-like*/ = /* see description */;

(2) (since C++20)
(exposition only*)

1) /*is-integer-like*/<T> is true if and only if T is an integer-like type.

2) /*is-signed-integer-like*/<T> is true if and only if T is a signed-integer-like type.

[edit] Integer-class type

A type T is an integer-class type if it is in a set of implementation-defined types that behave as integer types do, as defined below. An integer-class type is not necessarily a class type.

An integer-class type can represent \(\scriptsize 2^N \)2N consecutive integers, where N, a positive integer, is called the width of the integer-class type.

An integer-class type is either signed or unsigned:

A signed integer class type can represent all integers in [\(\scriptsize -2^{N-1} \)-2N-1 , \(\scriptsize 2^{N-1}-1 \)2N-1 -1], where N is greater than the width of every signed integral type.
An unsigned integer class type can represent all integers in [\(\scriptsize 0 \)0, \(\scriptsize 2^N-1 \)2N -1], where N is greater than the width of every unsigned integral type.

All integer-class types model regular and three_way_comparable<std::strong_ordering>.

A value-initialized object of integer-class type has value â0â.

An expression E of integer-class type T is contextually convertible to bool as if by bool(E != T(0)).

[edit] Integer-like type

A type other than (possibly cv-qualified) bool is integer-like if it models integral or if it is an integer-class type.

An integer-like type is signed-integer-like if it models signed_integral or if it is a signed-integer-class type.
An integer-like type is unsigned-integer-like if it models unsigned_integral or if it is an unsigned-integer-class type.

[edit] Required behaviors

Expressions of integer-class type are explicitly convertible to any integer-like type, and implicitly convertible to any integer-class type of equal or greater width and the same signedness. Expressions of integral type are both implicitly and explicitly convertible to any integer-class type. Conversions between integral and integer-class types and between two integer-class types do not exit via an exception. The result of such a conversion is the unique value of the destination type that is congruent to the source modulo \(\scriptsize 2^N \)2N, where N is the width of the destination type.

Let Int<T> denote the following type:

If T is an integer-class type, Int<T> is a unique hypothetical extended integer type of the same signedness with the same width as T.
If T is an integral type, let Int<T> is the same type as T.

Given the following types, values and operators:

Type Definition IC an integer-class type IL an integer-like type Value Definition a an object of type IC b an object of type IL c an lvalue of an integeral type x an object of type Int<IC> that represent the same value as a y an object of type Int<IL> that represent the same value as b Operator Definition @= one of +=, -=, *=, /=, %=, &=, |=, ^=, <<= and >>= @ one of +, -, *, /, %, &, |, ^, <<, >>, &&, ||, ==, !=, <, >, <=, >=, <=> and ,

The following expressions must be well-formed and have their specified result and effects if the specified conditions are satisfied:

Expression Condition Result Effects a++ No condition a prvalue of type IC whose value is equal to that of a prior to the evaluation modifies the value of a by adding 1 to it a-- modifies the value of a by subtracting 1 to it ++a expression-equivalent to a += 1 --a expression-equivalent to a -= 1 &a expression-equivalent to std::addressof(a) !a !x is well-formed same as !x +a +x is well-formed same as +x, but has type IC same as +x -a -x is well-formed same as -x, but has type IC same as -x ~a ~x is well-formed same as ~x, but has type IC same as ~x c @= a c @= x is well-formed an lvalue referring to c same as c @= x a @= b x @= y is well-formed an lvalue referring to a same as x @= y, except that the value that would be stored into x is stored into a a @ b x @ y is well-formed same as x @ y, but the result type is different:

If x @ y is of type Int<IC>, the result has type IC.
If x @ y is of type Int<IL>, the result has type IL.
If x @ y is of any other type T, the result has type T.

same as x @ y b @ a y @ x is well-formed same as y @ x, but the result type is different:

If y @ x is of type Int<IC>, the result has type IC.
If y @ x is of type Int<IL>, the result has type IL.
If y @ x is of any other type T, the result has type T.

same as y @ x [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 3366
(P2393R1) C++20 the conversion between an integer-class type and its corresponding
integer type was not guaranteed to produce a representable value guaranteed LWG 3376
(P2393R1) C++20 integer-class types could only be class types also allowed
non-class types LWG 3467 C++20 bool was considered as an integer-like type excluded LWG 3575
(P2393R1) C++20 integer-class types were not guaranteed to be three-way-comparable guaranteed [edit] See also

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Showing content from https://en.cppreference.com/w/cpp/language/../iterator/is-integer-like.html below:

is-integer-likeâï»¿, is-signed-integer-like - cppreference.com

is-integer-likeâï»¿, is-signed-integer-like - cppreference.com