by-value methods show as inherited by Deref in Rustdoc

[elinorbgr]

See for example: http://vberger.github.io/wayland-client-rs/wayland_client/cursor/struct.CursorImageBuffer.html

Unless the target type is Copy, it is not possible to call a method taking a self argument (it would result in a "cannot move out of borrowed content" error), so showing these methods as available in the docs is erroneous.

[alexcrichton]

Discussion happened on #33396, but the conclusion was that we probably don't want to do this, so I'm going to close this.