bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/display.rs')
-rw-r--r--crates/hir-ty/src/display.rs49
1 files changed, 47 insertions, 2 deletions
diff --git a/crates/hir-ty/src/display.rs b/crates/hir-ty/src/display.rs
index a4e052a036..3545bf7677 100644
--- a/crates/hir-ty/src/display.rs
+++ b/crates/hir-ty/src/display.rs
@@ -471,10 +471,55 @@ impl HirDisplay for ProjectionTy {
if f.should_truncate() {
return write!(f, "{TYPE_HINT_TRUNCATION}");
}
-
let trait_ref = self.trait_ref(f.db);
+ let self_ty = trait_ref.self_type_parameter(Interner);
+
+ // if we are projection on a type parameter, check if the projection target has bounds
+ // itself, if so, we render them directly as `impl Bound` instead of the less useful
+ // `<Param as Trait>::Assoc`
+ if !f.display_target.is_source_code() {
+ if let TyKind::Placeholder(idx) = self_ty.kind(Interner) {
+ let db = f.db;
+ let id = from_placeholder_idx(db, *idx);
+ let generics = generics(db.upcast(), id.parent);
+
+ let substs = generics.placeholder_subst(db);
+ let bounds = db
+ .generic_predicates(id.parent)
+ .iter()
+ .map(|pred| pred.clone().substitute(Interner, &substs))
+ .filter(|wc| match wc.skip_binders() {
+ WhereClause::Implemented(tr) => {
+ match tr.self_type_parameter(Interner).kind(Interner) {
+ TyKind::Alias(AliasTy::Projection(proj)) => proj == self,
+ _ => false,
+ }
+ }
+ WhereClause::TypeOutlives(t) => match t.ty.kind(Interner) {
+ TyKind::Alias(AliasTy::Projection(proj)) => proj == self,
+ _ => false,
+ },
+ // We shouldn't be here if these exist
+ WhereClause::AliasEq(_) => false,
+ WhereClause::LifetimeOutlives(_) => false,
+ })
+ .collect::<Vec<_>>();
+ if !bounds.is_empty() {
+ return write_bounds_like_dyn_trait_with_prefix(
+ f,
+ "impl",
+ Either::Left(
+ &TyKind::Alias(AliasTy::Projection(self.clone())).intern(Interner),
+ ),
+ &bounds,
+ SizedByDefault::NotSized,
+ );
+ };
+ }
+ }
+
write!(f, "<")?;
- trait_ref.self_type_parameter(Interner).hir_fmt(f)?;
+ self_ty.hir_fmt(f)?;
write!(f, " as ")?;
trait_ref.hir_fmt(f)?;
write!(