[Bug c++/55581] New: Too-eager instantiation

[dave at boostpro dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55581

             Bug #: 55581
           Summary: Too-eager instantiation
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dave@boostpro.com


IMO this program should compile with -ftemplate-depth=1, as it does on Clang. 
[Sorry for the inline code; technical difficulties prevent me from adding an
attachment before I reboot my machine]


template <long N>
struct mooch
{
    struct arrow
    {
        mooch<N-1> operator->();
    };
    arrow operator->();
};

template <>
struct mooch<0>
{
    int x;

    mooch<0>* operator->();
};

mooch<10000> a;             // compiles with -ftemplate-depth 1
decltype(a.operator->()) y; // compiles with -ftemplate-depth 1
decltype(a->x) z;           // requires -ftemplate-depth=20000 on g++ but not
on clang++