error: use of `format!` to build up a string from an iterator --> $DIR/format_collect.rs:5:5 | LL | bytes.iter().map(|b| format!("{b:02X}")).collect() | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | help: call `fold` instead --> $DIR/format_collect.rs:5:18 | LL | bytes.iter().map(|b| format!("{b:02X}")).collect() | ^^^ help: ... and use the `write!` macro here --> $DIR/format_collect.rs:5:26 | LL | bytes.iter().map(|b| format!("{b:02X}")).collect() | ^^^^^^^^^^^^^^^^^^ = note: this can be written more efficiently by appending to a `String` directly = note: `-D clippy::format-collect` implied by `-D warnings` error: use of `format!` to build up a string from an iterator --> $DIR/format_collect.rs:19:5 | LL | / (1..10) LL | | .map(|s| { LL | | let y = 1; LL | | format!("{s} {y}") LL | | }) LL | | .collect() | |__________________^ | help: call `fold` instead --> $DIR/format_collect.rs:20:10 | LL | .map(|s| { | ^^^ help: ... and use the `write!` macro here --> $DIR/format_collect.rs:22:13 | LL | format!("{s} {y}") | ^^^^^^^^^^^^^^^^^^ = note: this can be written more efficiently by appending to a `String` directly error: aborting due to 2 previous errors