Defined in header <type_traits> | ||||
---|---|---|---|---|
| (since C++11) |
If T
is a PODType
("plain old data type"), that is, both trivial and standard-layout, provides the member constant value
equal true
. For any other type, value
is false
.
The behavior is undefined if std::remove_all_extents_t<T>
is an incomplete type and not (possibly cv-qualified) void
.
Template parameters
T | - | a type to check |
Helper variable template
| (since C++17) |
Inherited from std::integral_constant
Member constants
value [static] | true if T is a POD 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
Objects of POD types are fully compatible with the C programming language.
Example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | #include <iostream> #include <type_traits> struct A { int m; }; struct B { int m1; private : int m2; }; struct C { virtual void foo(); }; int main() { std::cout << std::boolalpha; std::cout << std::is_pod<A>::value << '\n' ; std::cout << std::is_pod<B>::value << '\n' ; std::cout << std::is_pod<C>::value << '\n' ; } |
Output:
1 2 3 | true false false |
See also
(C++11) | checks if a type is standard-layout type (class template) |
(C++11) | checks if a type is trivial (class template) |
std::experimental::is_pod_v
(library fundamentals TS) | variable template alias of std::is_pod::value (variable template) |
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