Re: c++/3400: doesn't compile simple hierarchy with overlaoding

["Artem Khodush" <artem@duma.gov.ru>]

The following reply was made to PR c++/3400; it has been noted by GNATS.

From: "Artem Khodush" <artem@duma.gov.ru>
To: <volker.reichenberger@iwr.uni-heidelberg.de>
Cc: <gcc-gnats@gcc.gnu.org>, <gcc-bugs@gcc.gnu.org>
Subject: Re: c++/3400: doesn't compile simple hierarchy with overlaoding
Date: Tue, 26 Jun 2001 11:56:20 +0400

 > 
 > class A {public: void a() {};};class B: public A {public: void a(int n) {};};int main(void){ B b; b.a(); return 0;}
 > 
 > I get the error message:
 > 
 > test.cc: In function `int main()':
 > test.cc:15: no matching function for call to `B::a ()'
 > test.cc:8: candidates are: void B::a(int)
 > 
 > I believe the code is correct (so do all my colleagues). 
 
 Nope. See the quote from the c++ standard below. In GCC 3.0,
 you can fix the code by putting 
   using A::a();
 into the class B.
 
   13.2  Declaration matching                                  [over.dcl]
 
 1 Two function declarations of the same name refer to the same  function
   if  they  are in the same scope and have equivalent parameter declara-
   tions (_over.load_).  A function member of a derived class is  not  in
   the  same scope as a function member of the same name in a base class.
   [Example:
 
           class B {
           public:
               int f(int);
           };
 
           class D : public B {
           public:
               int f(char*);
           };
   Here D::f(char*) hides B::f(int) rather than overloading it.
           void h(D* pd)
           {
               pd->f(1);       // error:
                               // D::f(char*) hides B::f(int)
               pd->B::f(1);    // ok
               pd->f("Ben");   // ok, calls D::f
           }
    --end example]