[Bug c++/12041] New: No overload search in evaluation of template parameter default value

["raoulgough at yahoo dot co dot uk" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12041

           Summary: No overload search in evaluation of template parameter
                    default value
           Product: gcc
           Version: 3.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: raoulgough at yahoo dot co dot uk
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i686-pc-mingw

How to reproduce. File overload.cc:

-----8<-------
struct A { };
struct B { };

char foo (A const &);
short foo (B const &);

template<typename T, unsigned Size = sizeof(foo(T()))>
struct bar {};

int main () {
  bar<A>();
  bar<B>();
}
-----8<-------

$ g++ -c overload.cc
overload.cc: In function `int main()':
overload.cc:11: error: could not convert `A()' to `const B&'
overload.cc:5: error: in passing argument 1 of `short int foo(const B&)'
overload.cc:11: error: template argument 2 is invalid

I think that this is *different* to bug 6424 and core language issue 339 
because it does not involve any function template parameter deduction (and the 
error message is different, too). It seems like g++ is only considering the 
most recently seen version of foo(), since reversing the declaration order of 
the two overloads produces a transposed error message:

short foo (B const &);
char foo (A const &);

// ...

overload.cc: In function `int main()':
overload.cc:12: error: could not convert `B()' to `const A&'
overload.cc:5: error: in passing argument 1 of `char foo(const A&)'
overload.cc:12: error: template argument 2 is invalid