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Showing content from https://en.cppreference.com/w/cpp/language/../error/../language/../types/is_integral.html below:

std::is_integral - cppreference.com

template< class T > struct is_integral;

(since C++11)

std::is_integral is a UnaryTypeTrait.

Checks whether T is an integral type. Provides the member constant value which is equal to true, if T is the type bool, char, char8_t(since C++20), char16_t, char32_t, wchar_t, short, int, long, long long, or any implementation-defined extended integer types, including any signed, unsigned, and cv-qualified variants. Otherwise, value is equal to false.

If the program adds specializations for std::is_integral or std::is_integral_v, the behavior is undefined.

[edit] Template parameters [edit] Helper variable template

template< class T > constexpr bool is_integral_v = is_integral<T>::value;

(since C++17) Inherited from std::integral_constant Member constants true if T is an integral type, false otherwise
(public static member constant) Member functions converts the object to bool, returns value
(public member function) returns value
(public member function) Member types [edit] Possible implementation

// Note: this implementation uses C++20 facilities
template<class T>
struct is_integral : std::bool_constant<
    requires (T t, T* p, void (*f)(T)) // T* parameter excludes reference types
    {
        reinterpret_cast<T>(t); // Exclude class types
        f(0); // Exclude enumeration types
        p + t; // Exclude everything not yet excluded but integral types
    }> {};

[edit] Example

#include <type_traits>
 
static_assert
(
    std::is_integral_v<float> == false &&
    std::is_integral_v<int*> == false &&
    std::is_integral_v<int> == true &&
    std::is_integral_v<const int> == true &&
    std::is_integral_v<bool> == true &&
    std::is_integral_v<char> == true
);
 
class A {};
static_assert(std::is_integral_v<A> == false);
 
struct B { int x:4; };
static_assert(std::is_integral_v<B> == false);
using BF = decltype(B::x); // bit-field's type
static_assert(std::is_integral_v<BF> == true);
 
enum E : int {};
static_assert(std::is_integral_v<E> == false);
 
template <class T>
constexpr T same(T i)
{
    static_assert(std::is_integral<T>::value, "Integral required.");
    return i;
}
static_assert(same('"') == 042);
 
int main() {}

[edit] See also specifies that a type is an integral type
(concept) [edit] identifies integer types
(public static member constant of std::numeric_limits<T>) [edit] checks if a type is a floating-point type
(class template) [edit] checks if a type is an arithmetic type
(class template) [edit] checks if a type is an enumeration type
(class template) [edit]

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