Re: [boost] [Config] Support for switching between std:: and boost:: equivalents.

On 6/5/2015 8:14 PM, Rob Stewart wrote:

On June 5, 2015 10:42:50 AM EDT, Edward Diener wrote:

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On June 5, 2015 5:30:03 AM EDT, Edward Diener wrote:

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It is very easy to use. For library 'XXX':

1) Just include the particular Boost.config header provided for a particular interoperable library XXX:

#include

I noticed in your PR that you also provide a header to get all such

On 6/5/2015 10:00 AM, Rob Stewart wrote: headers at once. I wonder whether the individual headers are really that useful. You could keep the implementation you have, but just document the one header.

The one header is documented. I have the individual headers to avoid flooding the macro namespaces with lots of macros you are not going to use.

I know you documented the everything header. I was suggesting that you not document or mention the others.

I don't think the flooding issue you mention is significant. The macro names are reasonably unique and I don't think there are so many that you need worry about defining them all.

I think giving people choices is better than not doing so. Why bring in what isn't needed for any give TU ?

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2) Include that library's main header file using the macro provided for that library:

#include BOOST_CPP_XXX_HDR

Why do you have "CPP" in that name? BOOST_XXX_HDR would seem sufficient. I also would suggest using HEADER rather than HDR.

I like to avoid macro name clashes, Having a common prefix, such as CPP, tends to do that.

I understand the concern, but I don't think BOOST_ATOMIC_HEADER, BOOST_ATOMIC_NAMESPACE, BOOST_ATOMIC_IS_STD, etc. would be likely to clash.

Actually I do, and I think you are wrong. It is customary for Boost libraries which have macros to name them starting with BOOST_XXX_ where XXX is the library name. Why should I worry about potential clashes by following the exacts same convention for my macros. OTOH I do like your suggestion about changing the name of the BOOST_CPP_HAS_XXX macros to something like BOOST_CPP_XXX_IS_STD, or better yet BOOST_CPP_XXX_USES_STD_LIB, as being much more descriptive even if less terse.

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I could even change BOOST_CPP_XXX_NS to BOOST_CPP_XXX_NAMESPACE and have everybody type out the fully explicit names.

HEADER won't appear very often, so I thought spelling it out would be fine. The namespace macro might be used more often, so I didn't suggest expanding it. OTOH, the longer name can be mitigated by a namespace alias.

OK, that seems reasonable. the BOOST_CPP_XXX_HEADER would only be used once each TU so I agree with you on that. No need for the HDR abbreviation. I want to wait until all discussion of the macros are complete before I implement macro naming changes, but I do appreciate your suggestions.