Where did WIN32_LEAN_AND_MEAN come from?
Commenter asdf wonders where came from. The symbol was introduced in the Windows 95 time frame as a way to exclude a bunch of Windows header files when you include . You can take a look at your file to see which ones they are. The symbol was added as part of the transition from 16-bit Windows to 32-bit Windows. The 16-bit header file di...