Splitting C++ REST SDK about cpprestsdk

[ras0219-msft]

This is a really interesting idea, but it would be a large restructuring of the project so we need to be careful and ensure it's the right thing to do.

As an experiment, adding macros to selectively disable parts of the library might be an interesting approach (we currently have a CPPREST_EXCLUDE_WEBSOCKETS macro which disables websockets; this also removes the need for Boost and OpenSSL on Windows).

+1

I only need PPLX. It would be good if it could be split from the cpprestsdk project

[cmazakas]

I was actually looking into making the cross-platform port of the PPL stand-alone. ras, you mention that it would require a large restructuring of the code. Is it not simply possible to copy the pplx directory and then create a new CMakeLists.txt file from that?

This section of the PPL is actually pretty useful and really should be available to everyone because there's no good libraries out there that seem to match what MS has created here.

[jason-ha]

I have project with the same needs. My project also needed narrow character width support on Windows. I tackled the latter first and have completed infrastructure to isolate components include pplx and json. Please see #1204. In CMake you may depend on cpprest_json and/or cpprest_pplx.
Note: I have not tested out referencing both in my project yet, but it should play out just fine.