std::is_integral (3) - Linux Manuals

std::is_integral: std::is_integral

NAME

std::is_integral - std::is_integral

Synopsis

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

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, 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

T - a type to check

Helper variable template

template< class T > (since C++17)
inline constexpr bool is_integral_v = is_integral<T>::value;

Inherited from std::integral_constant

Member constants

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

Member functions

              converts the object to bool, returns value
operator bool (public member function)

operator() returns value
              (public member function)
(C++14)

Member types

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

Example

// Run this code

  #include <iostream>
  #include <type_traits>

  class A {};

  enum E : int {};

  template <class T>
  T f(T i)
  {
      static_assert(std::is_integral<T>::value, "Integral required.");
      return i;
  }

  int main()
  {
      std::cout << std::boolalpha;
      std::cout << std::is_integral<A>::value << '\n';
      std::cout << std::is_integral<E>::value << '\n';
      std::cout << std::is_integral<float>::value << '\n';
      std::cout << std::is_integral<int>::value << '\n';
      std::cout << std::is_integral<bool>::value << '\n';
      std::cout << f(123) << '\n';
  }

Output:

  false
  false
  false
  true
  true
  123