rust/tests/ui/suggestions/match-needing-semi.rs

// check-only

fn main() {
    match 3 {
        4 => 1,
        3 => {
            foo() //~ ERROR mismatched types
        }
        _ => 2
    }
    match 3 { //~ ERROR mismatched types
        4 => 1,
        3 => 2,
        _ => 2
    }
    let _ = ();
}

fn foo() -> i32 {
    42
}
review comments 2019-09-27 20:35:34 -05:00			`// check-only`
Point at enclosing match when expecting `()` in arm When encountering code like the following: ```rust fn main() { match 3 { 4 => 1, 3 => { println!("Yep it maches."); 2 } _ => 2 } println!("Bye!") } ``` point at the enclosing `match` expression and suggest ignoring the returned value: ``` error[E0308]: mismatched types --> $DIR/match-needing-semi.rs:8:13 \| LL \| / match 3 { LL \| \| 4 => 1, LL \| \| 3 => { LL \| \| 2 \| \| ^ expected (), found integer LL \| \| } LL \| \| _ => 2 LL \| \| } \| \| -- help: consider using a semicolon here \| \|_____\| \| expected this to be `()` \| = note: expected type `()` found type `{integer} ``` Fix #40799. 2019-09-26 19:16:34 -05:00
			`fn main() {`
			`match 3 {`
			`4 => 1,`
			`3 => {`
Do not suggest `;` if expression is side effect free When a tail expression isn't unit, we previously always suggested adding a trailing `;` to turn it into a statement. This suggestion isn't appropriate for any expression that doesn't have side-effects, as the user will have likely wanted to call something else or do something with the resulting value, instead of just discarding it. 2021-02-04 19:36:06 -06:00			`foo() //~ ERROR mismatched types`
Point at enclosing match when expecting `()` in arm When encountering code like the following: ```rust fn main() { match 3 { 4 => 1, 3 => { println!("Yep it maches."); 2 } _ => 2 } println!("Bye!") } ``` point at the enclosing `match` expression and suggest ignoring the returned value: ``` error[E0308]: mismatched types --> $DIR/match-needing-semi.rs:8:13 \| LL \| / match 3 { LL \| \| 4 => 1, LL \| \| 3 => { LL \| \| 2 \| \| ^ expected (), found integer LL \| \| } LL \| \| _ => 2 LL \| \| } \| \| -- help: consider using a semicolon here \| \|_____\| \| expected this to be `()` \| = note: expected type `()` found type `{integer} ``` Fix #40799. 2019-09-26 19:16:34 -05:00			`}`
			`_ => 2`
			`}`
			`match 3 { //~ ERROR mismatched types`
			`4 => 1,`
			`3 => 2,`
			`_ => 2`
			`}`
			`let _ = ();`
			`}`
Do not suggest `;` if expression is side effect free When a tail expression isn't unit, we previously always suggested adding a trailing `;` to turn it into a statement. This suggestion isn't appropriate for any expression that doesn't have side-effects, as the user will have likely wanted to call something else or do something with the resulting value, instead of just discarding it. 2021-02-04 19:36:06 -06:00
			`fn foo() -> i32 {`
			`42`
			`}`