Description
When reading about struct update syntax in The Book 2nd Edition, I wondered what would happen with Copy field members versus Clone field members versus neither. Googling around didn't help (if there's an RFC I couldn't find it) and eventually I just used the playground to figure out the behavior: Copy fields are copied, other fields are moved, possibly leading to a "partially moved" struct.
It would be nice if the book and/or reference spelled this out.
Citations:
https://doc.rust-lang.org/reference/expressions/struct-expr.html
"with [...] the values in the base expression for all other fields", 'with' is vague
https://doc.rust-lang.org/stable/book/second-edition/ch05-01-defining-structs.html
"use the rest of the values from the fields of the instance", 'use' is vague
https://doc.rust-lang.org/nightly/book/first-edition/structs.html#update-syntax
"it will copy the values", technically not true for non-Copy types
https://play.rust-lang.org/?gist=cb23fb3f9f9c631370b2b631367b8b16&version=stable
Example of a "partially moved value"