Okay, don't think in terms of function pairs, but in terms of use case. You might want to write unknown UTF16 to a file, and you might want to write UTF16 to a

Okay, don't think in terms of function pairs, but in terms of use case. You might want to write unknown UTF16 to a file, and you might want to write UTF16 to a filename. But only one of these is possible. Why? because there's an api for writing contents to a handle that takes a length, but not one for opening a file that does. And you can't “create” api's for what the kernel doesn't support. These are limits on what is possible without forking Linux or some other kernel.