[boost] Re: Re: Re: Re: Re: Re: New patch for operators.hpp uploaded

From: Daniel Frey (d.frey_at_[hidden])
Date: 2002-10-25 19:29:03

On Fri, 25 Oct 2002 17:49:28 +0200, David Abrahams wrote:

> Daniel Frey <d.frey_at_[hidden]> writes:
> 
>> On Thu, 24 Oct 2002 19:02:03 +0200, David Abrahams wrote:
>> 
>> >> The question is, why 'X x( f() );' is different from 'X x = f();'.
>> > 
>> > I remember having this conversation with the EDG guys last year. For
>> > people whose heads are deep in the core language, apparently it isn't
>> > obvious that they should be the same, and that it won't be obvious to
>> > users which form avoids the extra copy.
>> 
>> As I said earlier in this thread, the EDG-folks proved me wrong more
>> than once. Do you remember any details or their argumentation?
> 
> There was no argumentation, except on my part regarding what would be
> obvious to users. We all understood that both optimizations were
> optional.

I can understand that, but although it's optional, it's still surprising
to see it's not implemented. What I can keep in mind as a summary is, that
for EDG-based compilers 'X x = f();' is more efficient than 'X x( f() );',
for all other compilers it's equally good or bad. Thanks to all for the
testing and discussion.

Regards, Daniel