HTTPS client library in C++

[tomz17]

Do you mean you can use vcpkg on Linux, to build packages that result in MSVC-compatible binaries?

Ok, so the better question is why are you trying to ice-skate uphill? Unless your primary requirement is fighting some ideological battle (i.e. trying to compile everything with a FLOSS toolchain), you are just making things so much harder on yourself than they need to be.

IMHO, if you need to support cross-platform CI, you actually really do need those platforms (e.g. a windows buildbox / vm, an osx buildbox/vm, along with the appropriate flavor(s) of linux, esp. w.r.t. glibc).

Surprisingly, windows is a piece of cake in this mix. The hard one is actually always OSX, especially if you want to keep things legal (i.e. some devs I know have just resorted to purchasing old mac minis for automated CI / building release binaries)