Re: [boost] [c++11]

Subject: Re: [boost] [c++11]
From: Niall Douglas (ndouglas_at_[hidden])
Date: 2013-06-17 11:04:32

> > On 14 June 2013 17:21, Niall Douglas <ndouglas_at_[hidden]> wrote:
> >> So here's the question: is C++03 compiler and C++03 TR1 standard
> >> library support still an absolute, unnegotiable requirement for a
> >> library to become an official part of Boost?
> >
> > No.
> >
> > http://www.boost.org/development/requirements.html#Portability
> 
> I suspect this may come down to the review ultimately: I can imagine that
any
> library that was C++11 only would have a hard time getting through review
"as
> is", *unless* there's a really compelling reason for it to be that way
(and for
> some libraries that may well be the case).  However, I can also imagine a
library
> being developed as a C++11 only lib and only ported back to C++03 and/or
less
> capable compilers once it's stable (or vice versa).

Thanks John: you're the only one who actually answered my question.

I should quickly explain why rvalue ref support is so important to proposed
Boost.AFIO: it's a 100% batch API and therefore takes in batches of things
to do and returns out batches of results. That implies lots of passing
sequences of things around in STL containers, which without rvalue refs are
not cheap to copy. Therefore while we could get the library working on
C++03, I'd imagine max IOPS would be awful as all those container copy
constructors fire several times per API invocation.

Right now max IOPS is about 80,000 which is awful, and that's *with* C++11.
I'd expect that to be an order of magnitude slower without move
construction.

Niall

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