[Bug c++/27178] New: Failure to recognize template default type argument

[kreckel at ginac dot de]

Consider this piece of code:

template < typename T > class Alloc { };
template < typename T, typename A = Alloc< T > > class List { };
template < template < typename > class > class container;
typedef container< List > myotherlist;

This code compiles fine with gcc-3.x, gcc-4.0 and gcc-4.1 but with gcc-4.2.0
20060415 I get an "type/value mismatch at argument 1 in template parameter list
for 'template<template<class> class<template-parameter-1-1> > struct container
expected a template of type 'template<class> class<template-parameter-1-1>',
got 'template<class T, class A> class List'" error.

Changing the forward declaration of template class container makes it work:

template < template < typename, typename > class > class container;

This makes the default in the template type list of class List slightly
pointless.


-- 
           Summary: Failure to recognize template default type argument
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kreckel at ginac dot de
 GCC build triplet: i686-linux-gnu
  GCC host triplet: i686-linux-gnu
GCC target triplet: i686-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27178