Re: RFC: lalr1.cc: support move semantics

[Frank Heckenbach]

Hans Åberg wrote:

> >>>   Modern C++ (i.e., C++11 and later) introduced "move only" types: types 
> >>> such
> >>>   as std::unique_ptr<T> that can never be duplicated.  They must never be
> >>>   copied (by assignments and constructors), they must be "moved".  The
> >>>   implementation of lalr1.cc used to copy symbols (including their 
> >>> semantic
> >>>   values).  This commit ensures that values are only moved in modern C++, 
> >>> yet
> >>>   remain compatible with C++98/C++03.
> >> 
> >> Hopefully copy only types can still be used. So say:
> > 
> > C++ will automatically copy when copy is available and move is not.
> 
> Yes, but strictly, that is not what the above text says.

Depends on your definitions. IMHO in (modern) C++ "move" always
implies "copy" if possible and necessary, though I wouldn't object
to spelling it out here.

Regards,
Frank