File: suggest-return-closure.rs

package info (click to toggle)
rustc 1.87.0%2Bdfsg1-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 925,564 kB
  • sloc: xml: 158,127; python: 36,039; javascript: 19,761; sh: 19,737; cpp: 18,981; ansic: 13,133; asm: 4,376; makefile: 710; perl: 29; lisp: 28; ruby: 19; sql: 11
file content (41 lines) | stat: -rw-r--r-- 1,498 bytes parent folder | download | duplicates (7)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
fn fn_once() -> _ {
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types [E0121]
    //~| NOTE not allowed in type signatures
    //~| HELP replace with an appropriate return type
    //~| SUGGESTION impl FnOnce()
    //~| NOTE for more information on `Fn` traits and closure types
    let x = String::new();
    || {
        drop(x);
    }
}

fn fn_mut() -> _ {
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types [E0121]
    //~| NOTE not allowed in type signatures
    //~| HELP replace with an appropriate return type
    //~| SUGGESTION impl FnMut(char)
    //~| NOTE for more information on `Fn` traits and closure types
    let x = String::new();
    //~^ HELP: consider changing this to be mutable
    //~| NOTE binding `x` declared here
    |c| { //~ NOTE: value captured here
        x.push(c);
        //~^ ERROR: does not live long enough
        //~| NOTE: does not live long enough
        //~| NOTE: cannot borrow as mutable
        //~| ERROR: not declared as mutable
    }
} //~ NOTE: borrow later used here
//~^ NOTE: dropped here

fn fun() -> _ {
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types [E0121]
    //~| NOTE not allowed in type signatures
    //~| HELP replace with an appropriate return type
    //~| SUGGESTION impl Fn() -> i32
    //~| NOTE for more information on `Fn` traits and closure types
    || 1i32
}

fn main() {}