rust/tests/ui/fn/suggest-return-closure.rs

41 lines
1.4 KiB
Rust

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
|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() {}