Defined in header <type_traits> | ||
---|---|---|
template< class T > struct is_literal_type; | (since C++11) (deprecated in C++17) (removed in C++20) |
If T
satisfies all requirements of LiteralType, 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
.
T | - | a type to check |
template< class T > inline constexpr bool is_literal_type_v = is_literal_type<T>::value; | (since C++17) (deprecated) (removed in C++20) |
value
[static] | true if T is a literal type , false otherwise (public static member constant) |
operator bool | converts the object to bool , returns value (public member function) |
operator()
(C++14) | returns value (public member function) |
Type | Definition |
---|---|
value_type | bool |
type | std::integral_constant<bool, value> |
Only literal types may be used as parameters to or returned from constexpr functions. Only literal classes may have constexpr member functions.
#include <iostream> #include <type_traits> struct A { int m; }; struct B { virtual ~B(); }; int main() { std::cout << std::boolalpha; std::cout << std::is_literal_type<A>::value << '\n'; std::cout << std::is_literal_type<B>::value << '\n'; }
Output:
true false
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