error: methods with the following characteristics: (`to_*` and `self` type is not `Copy`) usually take `self` by reference --> $DIR/wrong_self_conventions_mut.rs:14:24 | LL | pub fn to_many(&mut self) -> Option<&mut [T]> { | ^^^^^^^^^ | = note: `-D clippy::wrong-self-convention` implied by `-D warnings` = help: consider choosing a less ambiguous name error: methods with the following characteristics: (`to_*` and `*_mut`) usually take `self` by mutable reference --> $DIR/wrong_self_conventions_mut.rs:22:28 | LL | pub fn to_many_mut(&self) -> Option<&[T]> { | ^^^^^ | = help: consider choosing a less ambiguous name error: aborting due to 2 previous errors