error: `to_string()` called on a `String`
  --> tests/ui/string_to_string_in_map.rs:8:23
   |
LL |     let _ = variable2.map(String::to_string);
   |                       ^^^^^^^^^^^^^^^^^^^^^^ help: try: `cloned()`
   |
note: the lint level is defined here
  --> tests/ui/string_to_string_in_map.rs:1:9
   |
LL | #![deny(clippy::string_to_string)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^

error: `to_string()` called on a `String`
  --> tests/ui/string_to_string_in_map.rs:10:23
   |
LL |     let _ = variable2.map(|x| x.to_string());
   |                       ^^^^^^^^^^^^^^^^^^^^^^ help: try: `cloned()`

error: `to_string()` called on a `String`
  --> tests/ui/string_to_string_in_map.rs:13:23
   |
LL |     let _ = variable2.map(|x| { x.to_string() });
   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `cloned()`

error: `to_string()` called on a `String`
  --> tests/ui/string_to_string_in_map.rs:16:40
   |
LL |     let _ = vec![String::new()].iter().map(String::to_string).collect::<Vec<_>>();
   |                                        ^^^^^^^^^^^^^^^^^^^^^^ help: try: `cloned()`

error: `to_string()` called on a `String`
  --> tests/ui/string_to_string_in_map.rs:18:40
   |
LL |     let _ = vec![String::new()].iter().map(|x| x.to_string()).collect::<Vec<_>>();
   |                                        ^^^^^^^^^^^^^^^^^^^^^^ help: try: `cloned()`

error: aborting due to 5 previous errors