[Bug c++/77984] Invalid warning on templated operator= with -Weffc++

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77984

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-08-22
                 CC|                            |egallager at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #5 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Victor Paléologue from comment #0)
> Created attachment 39810 [details]
> Stand-alone C++ code reproducing a false warning
> 
> In the code attached, Thing::operator= is defined as following:
> 
> struct Thing
> {
>   template<typename T>
>   Thing& operator=(const T&)
>   {
>     return *this;
>   }
> };
> 
> Compiling it, I get a warning that does not seem legitimate:
> 
> $ g++ false_warning.cpp -Weffc++
> false_warning.cpp: In member function ‘Thing& Thing::operator=(const T&)’:
> false_warning.cpp:6:13: warning: ‘operator=’ should return a reference to
> ‘*this’ [-Weffc++]
>      return *this;
>              ^~~~
> 

Confirmed.

(In reply to Jonathan Wakely from comment #4)
> No, but IMHO it should be (unless somebody fixes it, see PR 16166 and PR
> 16168 and PR 55837 and others).

I'd rather see it fixed; I might give it a try myself once I learn enough c++
to know what I'm doing. In the meantime I'll make a meta-bug to gather all the
-Weffc++ bugs together.