std::is_compound (3) Linux Manual Page

std::is_compound – std::is_compound

Synopsis

Defined in header<type_traits>

    template <class T>
    (since C++ 11)

        struct is_compound;

If T is a compound type (that is, array, function, object pointer, function pointer, member object pointer, member function pointer, reference, class, union, or enumeration, including any cv-qualified variants), provides the member constant value equal true. For any other type, value is false.

Template parameters

T – a type to check

Helper variable template

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

Inherited from std::integral_constant

Member constants

value true if T is a compound 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>

Notes

Compound types are the types that are constructed from fundamental types. Any C++ type is either fundamental or compound.

Possible implementation

  template< class T >
  struct is_compound : std::integral_constant<bool, !std::is_fundamental<T>::value> {};

Example

// Run this code

#include <iostream>

#include <type_traits>
int main()
{
    class cls
    {
    };
    std::cout << (std::is_compound<cls>::value
                      ? "T is compound"
                      : "T is not a compound")
              << '\n';
    std::cout << (std::is_compound<int>::value
                      ? "T is compound"
                      : "T is not a compound")
              << '\n';
}

Output:

  T is compound
  T is not a compound

See also

is_fundamental checks if a type is a fundamental type
               (class template)
(C++11)
is_scalar checks if a type is a scalar type
               (class template)
(C++11)
is_object checks if a type is an object type
               (class template)
(C++11)
is_array checks if a type is an array type
               (class template)
(C++11)