[Bug c++/49229] New: [C++0x][SFINAE] ICE with variadics and depending non-type default parameter

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49229

           Summary: [C++0x][SFINAE] ICE with variadics and depending
                    non-type default parameter
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: daniel.kruegler@googlemail.com
                CC: jason@redhat.com


gcc 4.7.0 20110528 (experimental) in C++0x mode produces an ICE with the
following program at the line marked with #:

//-----
extern void* enabler;

template<bool, class = void>
struct enable_if {};

template<class T>
struct enable_if<true, T> {
  typedef T type;
};

template<class... Bn>
struct and_;

template<class B1>
struct and_<B1> : B1 {};

template<class, class>
struct is_same {
  static constexpr bool value = false;
};

template<class T>
struct is_same<T, T> {
  static constexpr bool value = true;
};

template<class... T>
struct S {
  template<class... U,
    typename enable_if<and_<is_same<T, U>...>::value>::type*& = enabler
  >
  S(U...){} // #
};

S<bool> s(0);
//-----

"internal compiler error: tree check: expected tree_vec, have error_mark in
comp_template_args, at cp/pt.c:6534"

This bug is possibly related to bug 49225.