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On 14 June 2013 17:21, Niall Douglas wrote:

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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 --- Opinions expressed here are my own and do not necessarily represent those of BlackBerry Inc.