std::is_compound (3) - Linux Man Pages

std::is_compound: std::is_compound

NAME

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)