How to write multiported library?

AndrzejB

Especially using cmake.
For example most files is common, but several files are for Linux and other for Windows.
Or other example: library for SingleInstance using ICP irrespective of Qt5, Qt6 or WxWidgets.
Which is good practice for it?

ChrisW67

If you mean conditionally including files then something like this:

set(COMMON_SOURCES file1.cpp file2.cpp ... )
if (WIN32)
    set(PLATFORM_SOURCES win32file1.cpp win32file2.cpp ...}
elseif (UNIX)
    set(PLATFORM_SOURCES unixfile1.cpp unixfile2.cpp ...}
else()
  # generate error?
endif()

add_library(my_library ${COMMON_SOURCES} ${PLATFORM_SOURCES} )

or

use an explicitly set variable rather than the WIN32/UNIX pre-defined variables
detect the presence of the platform specific libraries in order to determine what to build

Or other example: library for SingleInstance using ICP irrespective of Qt5, Qt6 or WxWidgets.

No idea what "SingleInstance using ICP" means