Re: [boost] Re: Library TR draft available

From: Beman Dawes (bdawes_at_[hidden])
Date: 2004-11-10 17:26:10

At 11:24 AM 11/10/2004, David Abrahams wrote:
 >Beman Dawes <bdawes_at_[hidden]> writes:
 >
 >> The latest draft of the C++ Standard Library Technical Report is now
 >> available at
 >> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1711.pdf
 >>
 >> There may be editorial (non-substantiative) changes to the final
 >> version of the TR document, but this latest draft is believed to be
 >> final in terms of technical content. Thus it should be safe for
 >> implementors or users to write code based on this latest draft.
 >>
 >> It will be several years before most compilers come with a full
 >> implementation of the TR. But some vendors (Metrowerks, for example)
 >> are already shipping a few TR components. That brings up the question
 >> of what Boost code does during the transition.
 >>
 >> To insure Boost code works with various TR implementations, some Boost
 >> code will want to use the compiler vendor's version of the TR if the
 >> TR component required is available, but otherwise will want to use
 >> Boost equivalent code. How do we handle that?  The TR doesn't provide
 >> in configuration macros, so I guess we will have to roll our own.
 >
 >Provide a switch that allows Boost headers to #include the appropriate
 >TR components and re-publish them with using declarations?
 >
 >It's not perfect; there will be some differences in ADL behavior
 >because those types are actually in different namespaces.

That sounds like a possibility.

I was thinking of an approach that used a namespace alias. If a vendor's 
version of the TR was to be used, the alias would be to std::tr1, otherwise 
it would be to the appropriate boost sub-namespace. Which particular alias 
was used would be controlled by #ifdef's.

That approach would have some ADL issues too.

--Beman