---Offending Code---
#include <iostream>

class Foo
{

};

class Bar
{

};

template<class A>
class Handler
{
public:
   virtual void handle(A*) = 0; 
};

class Baz : public Handler<Foo>,
            public Handler<Bar>
{

};

class Foobar : public Baz
{
public:
   virtual void handle(Bar* bar)
   {
      std::cout << "handle bar" << std::endl;
   } 

   virtual void handle(Foo* foo)
   {
      std::cout << "handle foo" << std::endl;
   } 
};

int main()
{
   Foo* foo = new Foo();
   Baz* baz = new Foobar();
   baz->handle(foo);

   return 0;
}

--- compilation command ---
g++ test.cpp

--- compiler error ---
test.cpp: In function ‘int main()’:
test.cpp:45: error: request for member ‘handle’ is ambiguous
test.cpp:18: error: candidates are: void Handler<A>::handle(A*) [with A = Bar]
test.cpp:18: error:                 void Handler<A>::handle(A*) [with A = Foo]

--- notes ---
This error doesn't happen if Foobar doesn't exist and the interfaces are
implemented in Baz.


-- 
           Summary: erroneous ambiguous error for subclasses overloaded
                    templated interfaces
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: a dot clarke at techsmith dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36641

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