[Bug c++/56373] -Wzero-as-null-pointer-constant: does not catch issues with smart pointers

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56373

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-02-18 13:20:41 UTC ---
(In reply to comment #2)
> > It's necessary, because otherwise you get bogus warnings from ScopeGuard-style
> > RAII types.
> 
> In which case the constructor and destructor would be meaningful,
> which is not the case here.

~shared_ptr() has non-trivial side-effects, the compiler isn't smart enough to
determine they won't fire when its empty, so it's always meaningful.

If you're smart enough to know the object isn't used then don't create it :)