std::is_integral
From cppreference.com
| 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, 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 > inline 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
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
See also
| [static] |
identifies integer types (public static member constant of std::numeric_limits<T>) |
| (C++11) |
checks if a type is a floating-point type (class template) |
| (C++11) |
checks if a type is an arithmetic type (class template) |
| (C++11) |
checks if a type is an enumeration type (class template) |