[boost] Re: non-throwing assignment stronger than non-throwing swap (was Idea: Automatic Objects)

From: scleary_at_[hidden]
Date: 1999-12-29 12:31:41

> . . . That should be made explicit and highlighted in both
> the header and the documentation since a throwing constructor in the
> function object is an easy way to accidentally misuse the class.
>
Still working on the docs. . . Right now they aren't requirements-based.
This is on the "todo" list.

> But in your message, you equate non-throwing assignment with non-throwing
> swap. I want to emphasize that a non-throwing assignment is a much
stronger
> requirement than a non-throwing swap. The standard library swap is always
> non-throwing if copy construction, destruction, and assignment are
> non-throwing. But a non-throwing swap can be provided for classes where a
> non-throwing constructor or assignment operator would be impossible.
>

Agreed.  I see now that this can be a very useful idea.

        -Steve