rust-analyzer

diff --git a/crates/hir-ty/src/chalk_ext.rs b/crates/hir-ty/src/chalk_ext.rs
index 436fb31bcc..d1aebeff26 100644
--- a/crates/hir-ty/src/chalk_ext.rs
+++ b/crates/hir-ty/src/chalk_ext.rs

@@ -29,7 +29,6 @@ pub trait TyExt {

fn contains_unknown(&self) -> bool;

fn is_ty_var(&self) -> bool;

fn is_union(&self) -> bool;

- fn is_projection(&self) -> bool;

fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)>;

fn as_builtin(&self) -> Option<BuiltinType>;

@@ -102,13 +101,6 @@ impl TyExt for Ty {

matches!(self.adt_id(Interner), Some(AdtId(hir_def::AdtId::UnionId(_))))

}

- fn is_projection(&self) -> bool {

- matches!(

- self.kind(Interner),

- TyKind::Alias(AliasTy::Projection(_)) | TyKind::AssociatedType(_, _)

- )

- }

fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)> {

match self.kind(Interner) {

TyKind::Adt(AdtId(adt), parameters) => Some((*adt, parameters)),

diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index 880c2b4b41..bb558e533c 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs

@@ -704,27 +704,13 @@ impl<'a> InferenceContext<'a> {

type_mismatches.retain(|_, mismatch| {

mismatch.expected = table.resolve_completely(mismatch.expected.clone());

mismatch.actual = table.resolve_completely(mismatch.actual.clone());

- let unresolved_ty_mismatch = || {

- chalk_ir::zip::Zip::zip_with(

- &mut UnknownMismatch(self.db, |ty| matches!(ty.kind(Interner), TyKind::Error)),

- Variance::Invariant,

- &mismatch.expected,

- &mismatch.actual,

- )

- .is_ok()

- };

- let unresolved_projections_mismatch = || {

- chalk_ir::zip::Zip::zip_with(

- &mut UnknownMismatch(self.db, |ty| ty.contains_unknown() && ty.is_projection()),

- chalk_ir::Variance::Invariant,

- &mismatch.expected,

- &mismatch.actual,

- )

- .is_ok()

- };

- unresolved_ty_mismatch() && unresolved_projections_mismatch()

+ chalk_ir::zip::Zip::zip_with(

+ &mut UnknownMismatch(self.db),

+ Variance::Invariant,

+ &mismatch.expected,

+ &mismatch.actual,

+ )

+ .is_ok()

});

diagnostics.retain_mut(|diagnostic| {

use InferenceDiagnostic::*;

@@ -1666,16 +1652,13 @@ impl std::ops::BitOrAssign for Diverges {

*self = *self | other;

}

-/// A zipper that checks for unequal `{unknown}` occurrences in the two types.

-/// Types that have different constructors are filtered out and tested by the

-/// provided closure `F`. Commonly used to filter out mismatch diagnostics that

-/// only differ in `{unknown}`. These mismatches are usually not helpful, as the

-/// cause is usually an underlying name resolution problem.

-///

-/// E.g. when F is `|ty| matches!(ty.kind(Interer), TyKind::Unknown)`, the zipper

-/// will skip over all mismatches that only differ in `{unknown}`.

-struct UnknownMismatch<'db, F: Fn(&Ty) -> bool>(&'db dyn HirDatabase, F);

-impl<F: Fn(&Ty) -> bool> chalk_ir::zip::Zipper<Interner> for UnknownMismatch<'_, F> {

+/// A zipper that checks for unequal occurrences of `{unknown}` and unresolved projections

+/// in the two types. Used to filter out mismatch diagnostics that only differ in

+/// `{unknown}` and unresolved projections. These mismatches are usually not helpful.

+/// As the cause is usually an underlying name resolution problem

+struct UnknownMismatch<'db>(&'db dyn HirDatabase);

+impl chalk_ir::zip::Zipper<Interner> for UnknownMismatch<'_> {

fn zip_tys(&mut self, variance: Variance, a: &Ty, b: &Ty) -> chalk_ir::Fallible<()> {

let zip_substs = |this: &mut Self,

variances,

@@ -1746,7 +1729,12 @@ impl<F: Fn(&Ty) -> bool> chalk_ir::zip::Zipper<Interner> for UnknownMismatch<'_,

zip_substs(self, None, &fn_ptr_a.substitution.0, &fn_ptr_b.substitution.0)?

}

(TyKind::Error, TyKind::Error) => (),

- _ if (self.1)(a) || (self.1)(b) => return Err(chalk_ir::NoSolution),

+ (TyKind::Error, _)

+ | (_, TyKind::Error)

+ | (TyKind::Alias(AliasTy::Projection(_)) | TyKind::AssociatedType(_, _), _)

+ | (_, TyKind::Alias(AliasTy::Projection(_)) | TyKind::AssociatedType(_, _)) => {

+ return Err(chalk_ir::NoSolution)

+ }

_ => (),

}

diff --git a/crates/hir-ty/src/tests/diagnostics.rs b/crates/hir-ty/src/tests/diagnostics.rs
index fde90b0a55..119de7f050 100644
--- a/crates/hir-ty/src/tests/diagnostics.rs
+++ b/crates/hir-ty/src/tests/diagnostics.rs

@@ -141,7 +141,7 @@ impl Trait for () {

fn no_mismatches_with_unresolved_projections() {

check_no_mismatches(

r#"

-// Thing is {unknown}

+// `Thing` is `{unknown}`

fn create() -> Option<(i32, Thing)> {

Some((69420, Thing))

}