std::is_compound
Defined in header <type_traits> | ||
---|---|---|
template< class T >
struct is_compound;
| (since C++11) |
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 >
inline constexpr bool is_compound_v = is_compound<T>::value;
| (since C++17) |
Inherited from std::integral_constant
Member constants
value
[static] | true if T is a compound 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> |
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
#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
(C++11) | checks if a type is a fundamental type (class template) |
(C++11) | checks if a type is a scalar type (class template) |
(C++11) | checks if a type is an object type (class template) |
(C++11) | checks if a type is an array type (class template) |
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