[Bug c++/51424] New: [C++11] G++ should diagnose self-delegating constructors

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51424

             Bug #: 51424
           Summary: [C++11] G++ should diagnose self-delegating
                    constructors
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jason@gcc.gnu.org
                CC: pedro.lamarao@gmail.com, ville.voutilainen@gmail.com


This modification of g++.dg/template/meminit1.C should get a diagnostic in
C++11 mode as well:

template <class T >
struct S
{
  S() : S() {} // { dg-message "delegating constructors" "" { target c++98 } }
  // { dg-error "delegates to itself" "" { target c++11 } }
};

S<int> s;

because 12.6.2 says,

"If a constructor delegates to itself directly or indirectly, the program is
ill-formed; no diagnostic is required."

The diagnostic is not required, but it is easy to give, so we should do so.