Can I cast a derived class to a private base class, using C-style cast?
c++, casting, private-inheritance, upcasting
Solution
Yes you can: §5.4/7 of the standard:
... the following static_cast and reinterpret_cast operations (optionally followed by a const_cast operation) may be performed using the cast notation of explicit type conversion, even if the base class type is not accessible:
a pointer to an object of derived class type or an lvalue of derived class type may be explicitly converted to a pointer or reference to an unambiguous base class type, respectively;
But try not to as it defeats the purpose of private inheritance.
Problem
Can I do this? ``` class A { ... }; class B : private A { const A &foo() const { return *((const A *)this); } }; ``` Can I take a subclass that inherits privately from a base class and cast it to a public version of its base class? Can I do this without it having virtual methods? My guess is yes, but I wanted to make sure it's safe / portable.