Boost.Nowide Ready for release

From: Alexander Grund (alexander.grund_at_[hidden])
Date: 2020-03-04 15:24:31

Hi all,

after the discussion in January this year I took over maintenance of 
Boost.Nowide.

First goal: Integrate all changes and requests that came up during 
review and as Github Issues including the docs.
Second goal: Get extensive CI running with coverage especially on 
Windows (it is a mainly Windows library)
Third goal: Iron out bugs, performance issues and incompatibilities.

Of great help was my fork I prepared (and announced here) earlier but it 
was still an incredible amount of work.

I can now say I'm done!

I invite everyone to test it, (re-)review the code or check the docu for 
anything that's missing: https://github.com/boostorg/nowide

One of the bigger changes was to make the library "less header-only" (it 
already required compilation on Windows when using iostreams). This was 
due to some required functions being considered extensions by e.g. 
MinGW/Cygwin and hence failing for consumers build with `-std=c++98` (or 
similar). This now works!

Final note for those interested: The standalone (non-Boost) version and 
converter will be available later.

Happy poking!