[Bug c++/51270] missed warning about returning reference to temporary

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51270

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|constness violation is      |missed warning about
                   |accepted without any        |returning reference to
                   |warning but leads to a      |temporary
                   |required function call      |
                   |being eliminated during     |
                   |optimization                |

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-11-22 
16:41:16 UTC ---
Very similar to my PR 49974.


Still no warning even without the (highly questionable) cast:

char const* const& faulty_compiled_function(char*& val)
{
  char const* const& tmp = (const char*)val;
  return tmp;
}

N.B. Clang warns for that variation (but not the others):

faulty_optimization_of_invalid_const_usage.cpp:4:10: warning: returning
      reference to local temporary object [-Wreturn-stack-address]
  return tmp;
         ^~~
faulty_optimization_of_invalid_const_usage.cpp:3:22: note: binding reference
      variable 'tmp' here
  char const* const& tmp = (const char*)val;
                     ^     ~~~~~~~~~~~~~~~~