via https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros
_WIN32 Defined as 1 when the compilation target is 32-bit ARM, 64-bit ARM, x86, or x64. Otherwise, undefined.
_WIN64 Defined as 1 when the compilation target is 64-bit ARM or x64. Otherwise, undefined.
via https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros _WIN32 Defined as 1 when the compilation target is 32-bit ARM, 64-bit ARM, x86, or x64. Otherwise, undefined. _WIN64 Defined as 1 when the compilation target is 64-bit ARM or x64. Otherwise, undefined.