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std::is_integral

Defined in header `<type_traits>`
template< class T > struct is_integral;		(since C++11)

Checks whether T is an integral type. Provides the member constant value which is equal to true, if T is the type bool, char, 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.

Template parameters

a type to check

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

value

[static]

true if T is an integral type , false otherwise
(public static member constant)

Member functions

operator bool	converts the object to `bool`, returns `value` (public member function)
operator() (C++14)	returns `value` (public member function)

Member types

Type	Definition
`value_type`	`bool`
`type`	`std::integral_constant<bool, value>`

Example

#include <iostream>
#include <type_traits>
 
class A {};
 
template <class T>
T f(T i)
{
    static_assert(std::is_integral<T>::value, "Integer required.");
    return i;
}
 
int main() 
{
    std::cout << std::boolalpha;
    std::cout << std::is_integral<A>::value << '\n';
    std::cout << std::is_integral<float>::value << '\n';
    std::cout << std::is_integral<int>::value << '\n';
    std::cout << f(123) << '\n';
}

Output:

false
false
true
123

is_integer [static]	identifies integer types (public static member constant of `std::numeric_limits`)
is_floating_point (C++11)	checks if a type is floating-point type (class template)
is_arithmetic (C++11)	checks if a type is arithmetic type (class template)
std::experimental::is_integral_v (library fundamentals TS)	variable template alias of `std::is_integral::value` (variable template)

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