error[E0308]: mismatched types --> $DIR/issue-86100-tuple-paren-comma.rs:9:22 | LL | let _x: (i32,) = (5); | ------ ^^^ expected tuple, found integer | | | expected due to this | = note: expected tuple `(i32,)` found type `{integer}` help: use a trailing comma to create a tuple with one element | LL | let _x: (i32,) = (5,); | ~~~~ error[E0308]: mismatched types --> $DIR/issue-86100-tuple-paren-comma.rs:13:9 | LL | foo((Some(3))); | ^^^^^^^^^ expected tuple, found enum `Option` | = note: expected tuple `(_,)` found enum `Option<{integer}>` help: use a trailing comma to create a tuple with one element | LL | foo((Some(3),)); | ~~~~~~~~~~ error[E0308]: mismatched types --> $DIR/issue-86100-tuple-paren-comma.rs:17:22 | LL | let _s = S { _s: ("abc".to_string()) }; | ^^^^^^^^^^^^^^^^^^^ expected tuple, found struct `String` | = note: expected tuple `(String,)` found struct `String` help: use a trailing comma to create a tuple with one element | LL | let _s = S { _s: ("abc".to_string(),) }; | ~~~~~~~~~~~~~~~~~~~~ error[E0308]: mismatched types --> $DIR/issue-86100-tuple-paren-comma.rs:23:22 | LL | let _x: (i32,) = (t); | ------ ^^^ expected a tuple with 1 element, found one with 2 elements | | | expected due to this | = note: expected tuple `(i32,)` found tuple `({integer}, {integer})` error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0308`.