Such function checks if the binary is 64-bit, not if windows is 64-bit.
I interpreted the question as for which platform are we compiling? In his case that can be a 32 bit windows or a 64 bit windows.
My solution provides for that. (IOW a 64 bit compiler for a 64 bit Windows needs 64 bit libraries. A 32 bit compiler will download the 32 bit libraries even on a 64 bit windows)
My understanding is that is what he means. To be more precise it detects the target binaries, which he needs to download and install the target libraries.
But you know that.