CopyDir recursively copies all of the files within the directory given in src to the directory given in dst.

CopyFile copies the contents of the file named src to the file named by dst.

DeepCopyValue produces a deep copy of the given value, where the result ideally shares no mutable memory with the given value.

SameFile returns true if the two given paths refer to the same physical file on disk, using the unique file identifiers from the underlying operating system.