Subject: Re: [boost] [interest] underlying type library
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2011-08-22 14:06:16
Le 22/08/11 19:46, Nevin Liber a écrit :
> On 22 August 2011 10:30, Eric Niebler<eric_at_[hidden]> wrote:
>
>>> Do you still think that is easier than writing the move constructor and
>>> assignment operator for classes where the compiler generated one is wrong
>> or
>>> deleted?
>> I think it fills a different need.
>>
> Maybe at this point it would be nice if its proponents came up with a modern
> (i.e., why this would still be needed in a world with either C++11 or
> Boost.Move) motivating example or two. The Stepanov paper is a product of
> its time and no longer as useful for showing why we still need something
> like this.
move-raw as std::move are optimizations. In addition to the
optimizations introduced by std::move, move_raw don't need to left the
moved object in a stable state, so it could be in some cases, as Eric
told in another post, twice faster. This is the single reason to be for
move_raw: optimization.
We can define a RawMovable concept and traits that states if a type is
raw movable from another type (is_raw_movable). For these types we can
specialize some algorithms that benefit from this optimization. Note
that Movable will imply RawMovable if the default implementation uses
std::move.
Maybe this is not enough motivating for you, but it seem it is for others.
Best,
Vicente