#include <apibase.h>

详细描述

template<typename D, typename B>
struct maxon::HasBase< D, B >

This type trait checks if D has B as its base. This is the case if both are the same, or if both are virtual interfaces and D is (directly or indirecty) derived from B , or if D is derived from B as a C++ class.

若 D has B as its base, the function HasBase<D, B>Cast can be used to cast a pointer of the derived type to a pointer of the base type. This has to be used instead of a reinterpret_cast because the latter doesn't handle correctly cases with virtual classes or multiple inheritance when there are offsets between derived and base pointers.

Internally, if D has a member type HasBase , the check is forwarded to D::HasBase::Check<B> which implements the case for virtual interfaces. Otherwise, the check is simply forwarded to std::is_base_of<B, D> .

Template Parameters

D	Derived type to check (potential reference and const qualifiers are removed).
B	Base type to check (potential reference and const qualifiers are removed).