std::is_integral
Defined in header <type_traits>
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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
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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) |