[Bug c++/54909] New: gcc does not recognize member function template when identical named pure virtual method exists

[Bug c++/54909] New: gcc does not recognize member function template when identical named pure virtual method exists

[thomas.prescher at intel dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54909

             Bug #: 54909
           Summary: gcc does not recognize member function template when
                    identical named pure virtual method exists
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: thomas.prescher@intel.com


Created attachment 28432
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28432
test case

Hello,

I've found the following issue:

Assume you have a class A which has a pure-virtual method called foo which
gets one parameter. Furthermore, assume that A implements a template method
also called foo, which expects 0 arguments and has a template depended return
type.
Class B inherits from A and implements foo with one parameter.

When you call foo without parameter on an instance of B, gcc complains that it
expects a parameter, even if the template type is passed.

This is the error message, an example implementation is attached.

main.cc:33:20: error: expected primary-expression before ‘>’ token
main.cc:33:22: error: expected primary-expression before ‘)’ token

[Bug c++/54909] gcc does not recognize member function template when identical named pure virtual method exists

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54909

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-10-12 14:25:44 UTC ---
This is nothing to do with pure virtual functions, it's just the usual name
hiding rule.

You need to add "using A::foo;" to B to make the name visible.

[Bug c++/54909] gcc does not recognize member function template when identical named pure virtual method exists

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54909

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-10-12 14:28:00 UTC ---
The example can be reduced to

struct A
{
    template<class T> void foo() { } 
};

struct B : A
{
    void foo(int) { }
};

int main(int, char**)
{
    B b;
    b.foo<int>(); /* error */
}

An alternative to adding a using declaration is to qualify the function you
want:

    b.A::foo<int>();