[Bug libstdc++/49058] [C++0x] Bind no-arguments functor failed using std::bind with -pedantic option.

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49058

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-05-22 
21:23:12 UTC ---
It would be wrong though, consider:

struct F {
  int operator();
  void operator() const;
};

the decltype would detect the return type as 'int' but the function body would
return void, because _M_f is const