rust/tests/ui/suggestions/as-ref.rs
2023-06-08 16:30:05 +00:00

30 lines
1.3 KiB
Rust

struct Foo;
fn takes_ref(_: &Foo) {}
fn main() {
let ref opt = Some(Foo);
opt.map(|arg| takes_ref(arg)); //~ ERROR mismatched types [E0308]
opt.and_then(|arg| Some(takes_ref(arg))); //~ ERROR mismatched types [E0308]
let ref opt: Result<_, ()> = Ok(Foo);
opt.map(|arg| takes_ref(arg)); //~ ERROR mismatched types [E0308]
opt.and_then(|arg| Ok(takes_ref(arg))); //~ ERROR mismatched types [E0308]
let x: &Option<usize> = &Some(3);
let y: Option<&usize> = x; //~ ERROR mismatched types [E0308]
let x: &Result<usize, usize> = &Ok(3);
let y: Result<&usize, &usize> = x;
//~^ ERROR mismatched types [E0308]
// note: do not suggest because of `E: usize`
let x: &Result<usize, usize> = &Ok(3);
let y: Result<&usize, usize> = x; //~ ERROR mismatched types [E0308]
let multiple_ref_opt = &&Some(Foo);
multiple_ref_opt.map(|arg| takes_ref(arg)); //~ ERROR mismatched types [E0308]
multiple_ref_opt.and_then(|arg| Some(takes_ref(arg))); //~ ERROR mismatched types [E0308]
let multiple_ref_result = &&Ok(Foo);
multiple_ref_result.map(|arg| takes_ref(arg)); //~ ERROR mismatched types [E0308]
multiple_ref_result.and_then(|arg| Ok(takes_ref(arg))); //~ ERROR mismatched types [E0308]
let _: Result<&usize, _> = &Ok(42); //~ ERROR mismatched types [E0308]
}