[Bug c++/10126] ICE in convert_nontype_argument on using overload resolution in template args

["jason at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Additional Comments From jason at gcc dot gnu dot org  2003-12-02 05:51 -------
This testcase is ill-formed:

  5.3.1  Unary operators                                 [expr.unary.op]

2 The result of the unary & operator is a pointer to its  operand.   The
  operand  shall  be an lvalue or a qualified-id....  
                                                   For  a  qualified-id,
  if  the  member is a static member of type "T", the type of the result
  is plain "pointer to T."  If the member is a nonstatic member of class
  C  of  type T, the type of the result is "pointer to member of class C
  of type T."  [Example:

     struct A { int i; };
     struct B : A { };
     ... &B::i ...                 // has type int A::*

   --end example]

  14.3.2  Template non-type arguments                 [temp.arg.nontype]
  
  --  For  a  non-type  template-parameter  of  type  pointer  to member
      function,  no  conversions  apply.    If   the   template-argument
      represents  a  set  of  overloaded  member functions, the matching
      member function is selected from the set (_over.over_).

For better or worse, in this case worse, &Strawberry::I has type pointer to
member function of Fruit, not of Strawberry, and no conversion is done to make
it a pointer to member function of Strawberry.  To make it work, you need to add
an explicit downcast:

  dish.Get<(int const& (Strawberry::*fun)() const)&Strawberry::I>();

Dave, your testcase in 13040 is similarly ill-formed.

I'm not arguing that these rules make sense, but that is in fact what they say.

-- 
           What    |Removed                     |Added
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           Keywords|ice-on-valid-code           |ice-on-invalid-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10126