Question

I hope the title actually describes what I wanted to ask…

I wrote a piece of code that compiles with gcc and works as I intended. However, it does not compile with llvm and the code executes differently when compiled with icc!
Here is an example of the problem:

#include <iostream>

using std::cout; using std::endl;

class A {
public:
  virtual void foo() { cout << "A::foo()" << endl; }
};

class B : public A {
public:
  typedef A  base;
  virtual void foo() { cout << "B::foo()" << endl; }
};

int main() {
  typedef B  base;
  base* bp = new B();
  bp->base::foo(); 
}

gcc output: A::foo()
icc output: B::foo()

Could somebody explain what does the standard say about this case?

Answer 1

From C++11, §3.4.5/4:

If the id-expression in a class member access is a qualified-id of the
form

    class-name-or-namespace-name::...

the class-name-or-namespace-name
following the . or -> operator is first looked up in the class of the
object expression and the name, if found, is used. Otherwise it is
looked up in the context of the entire postfix-expression.

I don’t think it can be clearer. This finds B::base, so the output
should be A::foo().