std::meta::is_polymorphic_type
Defined in header <meta> | ||
|---|---|---|
consteval bool is_polymorphic_type( std::meta::info r ); | (since C++26) |
Returns true if r represents a polymorphic class (that is, a non-union class that declares or inherits at least one virtual function). Otherwise returns false.
Parameters
| r | - | a reflection value |
Return value
true if r represents a polymorphic class type; otherwise false.
Exceptions
Throws std::meta::exception if r does not represent a type or type alias.
Example
#include <meta>
struct A { int m; };
static_assert(!is_polymorphic_type(^^A));
struct B { virtual void foo(); };
static_assert(is_polymorphic_type(^^B));
struct C : B {};
static_assert(is_polymorphic_type(^^C));
struct D { virtual ~D() = default; };
static_assert(is_polymorphic_type(^^D));
// Virtual inheritance as such does not make a type polymorphic.
struct E : A {};
static_assert(!is_polymorphic_type(^^E));
struct F : virtual A {};
static_assert(!is_polymorphic_type(^^F));
struct AX : A {};
struct AY : A {};
struct XY : virtual AX, virtual AY {};
static_assert(!is_polymorphic_type(^^XY));
int main() {}
See also
|
(C++11) | checks if a type is a polymorphic class type (class template) |
|
(C++26) | checks if reflected type is a non-union class type (function) |
|
(C++26) | checks if reflected type is an abstract class type (function) |
|
(C++26) | checks if reflected type has a virtual destructor (function) |
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