Re: improve <boost/config.hpp>

From: John Maddock (jz.maddock_at_[hidden])
Date: 2023-03-07 18:14:13

> Please see: https://en.cppreference.com/w/cpp/feature_test for language
> level macros -- look for _cpp_constexpr.  I believe you'll discover that
> every combination you're looking for going back to cxx 2011 is represented
> -- basically making a boost config macro extraneous.  The standard copied
> this idea from boost.config btw and it's quite powerful for portable
> libraries.  Note that I regret using the boost.config macro for date-time
> constexpr stuff, because at this point I'd like to make the library
> available in a stand-alone fashion like boost.math.  Not depending on
> boost.config would be helpful in that endeavor.

I think that would be fairly trivial Jeff: I see nothing in date_time 
that requires something beyond C++11, so you could probably just check 
for Boost.Config's presence with __has_include and only include it when 
available.  Otherwise assume a conforming C++11 compiler in standalone mode.

John.