Re: [boost] Cxx dual library

On 6/3/2016 11:17 AM, Thomas Heller wrote:

Am 02.06.2016 8:56 nachm. schrieb "Edward Diener" :

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I have finished all the main work on the Cxx dual library at

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http://rrsd.com/blincubator.com/bi_library/cxx_dual-2/?gform_post_id=1597.

The Cxx dual library, or CXXD for short, is a C++ macro header-only

https://github.com/eldiener/cxx_dual. The library is also in the Boost Library Incubator at library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation' is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'dual library' in this documentation, or 'CXXD-mod' for short.

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The library does this by defining object-like macros for including the

appropriate header file and namespace or using either the Boost library version or the C++ standard library version of a particular dual library. CXXD currently supports twenty eight different dual libraries, where the Boost version and the C++ standard version is nearly interchangeable in some respects. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge.

Personally, I'm not a big fan of such a solution, especially when those macros "leak" into the public interface. We had a similar interface which would automatically switch between std and boost function. The result looked nice at first sight, however the subtle differences between the two led to various problems, one of which was that documenting the public interfaces containing this macro was very difficult, where does it point to know? Where should we send users to who look for more information about this function type? Should they be aware of both? Switching compilers or even boost version and now suddenly everything seems broken? The solution for us was to just decide which one to use and go with it, setting the requirements to the used standard library/boost version as needed.

You are not being very specific about the problems you encountered, so it is really hard to respond to them.