Turn label into structured suggestion for .as_ref() and .as_mut()

[estebank]

error[E0382]: use of moved value: `foo`
  --> $DIR/as-ref-2.rs:10:14
   |
LL |     let foo = Some(Struct);
   |         --- move occurs because `foo` has type `Option<Struct>`, which does not implement the `Copy` trait
LL |     let _x: Option<Struct> = foo.map(|s| bar(&s));
   |                                  ---------------- `foo` moved due to this method call
LL |     let _y = foo;
   |              ^^^ value used here after move
   |
note: `Option::<T>::map` takes ownership of the receiver `self`, which moves `foo`
  --> $SRC_DIR/core/src/option.rs:LL:COL
help: consider calling `.as_ref()` to borrow the value's contents
   |
LL |     let _x: Option<Struct> = foo.as_ref().map(|s| bar(&s));
   |                                 +++++++++
help: consider calling `.as_mut()` to mutably borrow the value's contents
   |
LL |     let _x: Option<Struct> = foo.as_mut().map(|s| bar(&s));
   |                                 +++++++++

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[JohnTitor]

Looks neat!
r? @JohnTitor @bors r+ rollup

View changes since this review

[rust-bors]

📌 Commit 7551181 has been approved by JohnTitor

It is now in the queue for this repository.