diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs index 3865175b6dc..54342f1b7c4 100644 --- a/crates/hir/src/lib.rs +++ b/crates/hir/src/lib.rs @@ -2791,14 +2791,19 @@ impl Impl { all } - // FIXME: the return type is wrong. This should be a hir version of - // `TraitRef` (to account for parameters and qualifiers) pub fn trait_(self, db: &dyn HirDatabase) -> Option { - let trait_ref = db.impl_trait(self.id)?.skip_binders().clone(); - let id = hir_ty::from_chalk_trait_id(trait_ref.trait_id); + let trait_ref = db.impl_trait(self.id)?; + let id = trait_ref.skip_binders().hir_trait_id(); Some(Trait { id }) } + pub fn trait_ref(self, db: &dyn HirDatabase) -> Option { + let substs = TyBuilder::placeholder_subst(db, self.id); + let trait_ref = db.impl_trait(self.id)?.substitute(Interner, &substs); + let resolver = self.id.resolver(db.upcast()); + Some(TraitRef::new_with_resolver(db, &resolver, trait_ref)) + } + pub fn self_ty(self, db: &dyn HirDatabase) -> Type { let resolver = self.id.resolver(db.upcast()); let substs = TyBuilder::placeholder_subst(db, self.id); @@ -2824,6 +2829,48 @@ impl Impl { } } +#[derive(Clone, PartialEq, Eq, Debug)] +pub struct TraitRef { + env: Arc, + trait_ref: hir_ty::TraitRef, +} + +impl TraitRef { + pub(crate) fn new_with_resolver( + db: &dyn HirDatabase, + resolver: &Resolver, + trait_ref: hir_ty::TraitRef, + ) -> TraitRef { + let env = resolver.generic_def().map_or_else( + || Arc::new(TraitEnvironment::empty(resolver.krate())), + |d| db.trait_environment(d), + ); + TraitRef { env, trait_ref } + } + + pub fn trait_(&self) -> Trait { + let id = self.trait_ref.hir_trait_id(); + Trait { id } + } + + pub fn self_ty(&self) -> Type { + let ty = self.trait_ref.self_type_parameter(Interner); + Type { env: self.env.clone(), ty } + } + + /// Returns `idx`-th argument of this trait reference if it is a type argument. Note that the + /// first argument is the `Self` type. + pub fn get_type_argument(&self, idx: usize) -> Option { + self.trait_ref + .substitution + .as_slice(Interner) + .get(idx) + .and_then(|arg| arg.ty(Interner)) + .cloned() + .map(|ty| Type { env: self.env.clone(), ty }) + } +} + #[derive(Clone, PartialEq, Eq, Debug)] pub struct Type { env: Arc,