Russian Qt Forum

C++ (Qt)
#include <iostream>
 
class Base {
public:
    virtual ~Base() {
 
    }
};
 
class Foo{
public:
    virtual ~Foo() {
 
    }
};
 
class FooBase: public Base, public Foo{    
};
 
int main()
{
    Base *base = new FooBase;
    Foo *foo = dynamic_cast<Foo *>(base);
    if (foo){
        std::cout << "yes";
    }
    else {
        std::cout << "no";
    }
}
 

C++ (Qt)
    Foo *foo = dynamic_cast<Foo *>(base);
 

C++ (Qt)
#include <stdio.h>
 
struct Root {
	virtual ~Root( void ) {}
};
 
struct Leaf1 {
	virtual ~Leaf1( void ) {}
};
 
struct Leaf2 {
	virtual ~Leaf2( void ) {}
};
 
struct Tree : public Root, public Leaf1, public Leaf2 {
};
 
int main( void )
{
	Tree * tree = new Tree;
	Leaf1 * leaf1 = tree;
	Leaf2 * leaf2 = dynamic_cast<Leaf2 *> (leaf1);
	printf("Tree = %p, Leaf1 = %p, Leaf2 = %p\n", tree, leaf1, leaf2);
	return 0;
}

C++ (Qt)
class A { virtual void f(); };
class B { virtual void g(); };
class D : public virtual A, private B { };
void g() {
    D d;
    B* bp = (B*)&d; // cast needed to break protection
    A* ap = &d; // public derivation, no cast needed
    D& dr = dynamic_cast<D&>(*bp); // fails
    ap = dynamic_cast<A*>(bp); // fails
    bp = dynamic_cast<B*>(ap); // fails
    ap = dynamic_cast<A*>(&d); // succeeds
    bp = dynamic_cast<B*>(&d); // ill-formed (not a run-time check)
}
 

C++ (Qt)
B* bp = (B*)&d; // cast needed to break protection

C++ (Qt)
B* bp = (B*)&d; // cast needed to break protection

C++ (Qt)
Leaf1 * leaf1 = new Leaf1;
Leaf1 * leaf1_1 = tree;