std::is_function

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

If T is function type (but not std::function, lambda expression or another callable object type), provides the member constant value equal true. For any other type, value is false.

Contents

Inherited from std::integral_constant

Member constants

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

Member functions

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

Member types

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

[edit] Example

#include <iostream>
#include <type_traits>
 
struct A {};
 
int f()
{
    return 1;
}
 
int main() 
{
    std::cout << std::boolalpha;
    std::cout << std::is_function<A>::value << '\n';
    std::cout << std::is_function<int(int)>::value << '\n';
    std::cout << std::is_function<decltype(f)>::value << '\n';
    std::cout << std::is_function<int>::value << '\n';
}

Output:

false
true
true
false

[edit] See also

(C++11)
checks if a type is object type
(class template)
(C++11)
checks if a type is a class type (but not union type)
(class template)