Re: [boost] [Review] Formal Review: Boost.Move - purpose + move enabling macros

Subject: Re: [boost] [Review] Formal Review: Boost.Move - purpose + move enabling macros
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2010-05-12 06:16:49

On 11/05/2010 8:48, Jeffrey Lee Hellrung, Jr. wrote:

> In my opinion, *the* primary goal of this library is to provide a
> standardized convention by which data structures and algorithms within
> and outside of boost can make use of move semantics in c++03 (there is
> already such a convention in c++0x).

The aim is also to provide a portable syntax between C++0x and C++03 
compilers, that's why I consider the macros necessary. I would like to 
offer a syntax any novice could easily understand.

I also understand your position when you say:

 > This means, for
> example, that, as an author of some class, I am not restricted to
> using the macros provided by this library to enable move emulation,
> or the forwarding functions this library provides, or whatever else,
> if they don't meet my requirements.

but I, as a writer of an algorithm, would like to know how the emulation 
works and what should I expect when assigning temporary copyable and 
movable classes. If the performance depends on the emulation used by the 
author, maybe I can't design the algorithm optimal for both C++0x and C++03.

> I believe an itemization of the
> nitty-gritty requirements that a class must satisfy to be move-aware
> will encourage alternative, more targeted methods to enable move
> emulation while remaining inter-compatible with each other.

As long as they are compatible, there is no problem, but I think having 
a C++0x-like syntax for move emulation is positive. Maybe both 
approaches should be available, the macro-based one for average users 
without forbidding the use of alternative approaches.

Thanks for your comments, best,

Ion