add va_list versions of log functions and add optional anonymous namespace

vicentebolea commented 2 years ago

These proposed changes are being used in the forked version Loguru used in ECP VTK-m.

Proposed changes are split into two commits:

Encapsulate functions using anonymous, needed for other libraries using this libraries not to export the loguru namespace to avoid possible conflict when there are two libraries/binaries using different Loguru versions and being statically linked together.
Add va_list version of the core functions, varadic MACROS are impossible to opaquely wrap, in this commit I propose an alternative.

vicentebolea commented 2 years ago

The CI error is unrelated to this changed and it is being fixed at #187

vicentebolea commented 2 years ago

I apply the fix at #187 to discard that there is any other error in those changes.

vicentebolea commented 2 years ago

@bylowerik thanks for the notice, rebased :)

emilk / loguru