fix: Panic while displaying associated function with a type annotation

This commit is contained in:
Shoyu Vanilla 2024-08-15 01:49:12 +09:00
parent 36a071c04d
commit f4b7e8100c
2 changed files with 35 additions and 8 deletions

View file

@ -1019,26 +1019,25 @@ impl HirDisplay for Ty {
let (parent_len, self_param, type_, const_, impl_, lifetime) =
generics.provenance_split();
let parameters = parameters.as_slice(Interner);
debug_assert_eq!(
parameters.len(),
parent_len + self_param as usize + type_ + const_ + impl_ + lifetime
);
// We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self?
if parameters.len() - impl_ > 0 {
// `parameters` are in the order of fn's params (including impl traits), fn's lifetimes
let parameters =
generic_args_sans_defaults(f, Some(generic_def_id), parameters);
let without_impl = self_param as usize + type_ + const_ + lifetime;
// parent's params (those from enclosing impl or trait, if any).
let (fn_params, parent_params) = parameters.split_at(without_impl + impl_);
debug_assert_eq!(parent_params.len(), parent_len);
let parent_params =
generic_args_sans_defaults(f, Some(generic_def_id), parent_params);
let fn_params =
&generic_args_sans_defaults(f, Some(generic_def_id), fn_params)
[0..without_impl];
write!(f, "<")?;
hir_fmt_generic_arguments(f, parent_params, None)?;
if !parent_params.is_empty() && !fn_params.is_empty() {
write!(f, ", ")?;
}
hir_fmt_generic_arguments(f, fn_params, None)?;
hir_fmt_generic_arguments(f, &fn_params[0..without_impl], None)?;
write!(f, ">")?;
}
}

View file

@ -8602,3 +8602,31 @@ fn test() {
"#]],
);
}
#[test]
fn issue_17871() {
check(
r#"
trait T {
fn f<A>();
}
struct S {}
impl T for S {
fn f<A>() {}
}
fn main() {
let x$0 = S::f::<i32>;
}
"#,
expect![[r#"
*x*
```rust
// size = 0, align = 1
let x: fn f<S, i32>()
```
"#]],
);
}