This is almost like the expression problem. Copy is a new operation, and you introduced a new type, thus creating a new grid cell nobody from either side could have reasonably known about - except for the fact Copy is in the standard library so you could have known about it but not done anything.
A good reminder. It is surprising first time you encounter it.
Same for Rust. As https://doc.rust-lang.org/stable/std/io/fn.copy.html says, std::io::copy can use copy_file_range(2), sendfile(2), or splice(2).
Zero-Copy in Go: Why magic is an antipattern, and: performance is observable behavior.
What would you prefer?
I do think it is criminal this is not documented (https://pkg.go.dev/io#Copy), but I think io.Copy is fine as an API.
it is documented by saying it calls ReadFrom or WriteTo
This is almost like the expression problem. Copy is a new operation, and you introduced a new type, thus creating a new grid cell nobody from either side could have reasonably known about - except for the fact Copy is in the standard library so you could have known about it but not done anything.
Ugh, AI slop writing.
Definitely written by codex.
Interesting premise for a post, but I had to stop midway due to the AI slop writing adding meaningless information.