error: calling `.extend(_.chars())` --> $DIR/string_extend.rs:18:5 | LL | s.extend(abc.chars()); | ^^^^^^^^^^^^^^^^^^^^^ help: try this: `s.push_str(abc)` | = note: `-D clippy::string-extend-chars` implied by `-D warnings` error: calling `.extend(_.chars())` --> $DIR/string_extend.rs:21:5 | LL | s.extend("abc".chars()); | ^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `s.push_str("abc")` error: calling `.extend(_.chars())` --> $DIR/string_extend.rs:24:5 | LL | s.extend(def.chars()); | ^^^^^^^^^^^^^^^^^^^^^ help: try this: `s.push_str(&def)` error: aborting due to 3 previous errors