1 files changed, 50 insertions, 7 deletions

diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 62eccf475..cc1938333 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -5,9 +5,7 @@ use arrayvec::ArrayVec;
 use base_db::{CrateDisplayName, CrateId, Edition, FileId};
 use either::Either;
 use hir_def::{
-    adt::ReprKind,
-    adt::StructKind,
-    adt::VariantData,
+    adt::{ReprKind, StructKind, VariantData},
     builtin_type::BuiltinType,
     expr::{BindingAnnotation, LabelId, Pat, PatId},
     import_map,
@@ -31,7 +29,7 @@ use hir_expand::{
 };
 use hir_ty::{
     autoderef,
-    display::{HirDisplayError, HirFormatter},
+    display::{write_bounds_like_dyn_trait, HirDisplayError, HirFormatter},
     method_resolution,
     traits::{FnTrait, Solution, SolutionVariables},
     ApplicationTy, BoundVar, CallableDefId, Canonical, DebruijnIndex, FnSig, GenericPredicate,
@@ -745,6 +743,18 @@ impl Function {
         db.function_data(self.id).name.clone()
     }
 
+    /// Get this function's return type
+    pub fn ret_type(self, db: &dyn HirDatabase) -> Type {
+        let resolver = self.id.resolver(db.upcast());
+        let ret_type = &db.function_data(self.id).ret_type;
+        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
+        let environment = TraitEnvironment::lower(db, &resolver);
+        Type {
+            krate: self.id.lookup(db.upcast()).container.module(db.upcast()).krate,
+            ty: InEnvironment { value: Ty::from_hir_ext(&ctx, ret_type).0, environment },
+        }
+    }
+
     pub fn self_param(self, db: &dyn HirDatabase) -> Option<SelfParam> {
         if !db.function_data(self.id).has_self_param {
             return None;
@@ -1278,6 +1288,18 @@ impl TypeParam {
         }
     }
 
+    pub fn trait_bounds(self, db: &dyn HirDatabase) -> Vec<Trait> {
+        db.generic_predicates_for_param(self.id)
+            .into_iter()
+            .filter_map(|pred| match &pred.value {
+                hir_ty::GenericPredicate::Implemented(trait_ref) => {
+                    Some(Trait::from(trait_ref.trait_))
+                }
+                _ => None,
+            })
+            .collect()
+    }
+
     pub fn default(self, db: &dyn HirDatabase) -> Option<Type> {
         let params = db.generic_defaults(self.id.parent);
         let local_idx = hir_ty::param_idx(db, self.id)?;
@@ -1293,6 +1315,20 @@ impl TypeParam {
     }
 }
 
+impl HirDisplay for TypeParam {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write!(f, "{}", self.name(f.db))?;
+        let bounds = f.db.generic_predicates_for_param(self.id);
+        let substs = Substs::type_params(f.db, self.id.parent);
+        let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
+        if !(predicates.is_empty() || f.omit_verbose_types()) {
+            write!(f, ": ")?;
+            write_bounds_like_dyn_trait(&predicates, f)?;
+        }
+        Ok(())
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct LifetimeParam {
     pub(crate) id: LifetimeParamId,
@@ -1331,6 +1367,12 @@ impl ConstParam {
     pub fn parent(self, _db: &dyn HirDatabase) -> GenericDef {
         self.id.parent.into()
     }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        let def = self.id.parent;
+        let krate = def.module(db.upcast()).krate;
+        Type::new(db, krate, def, db.const_param_ty(self.id))
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -1600,9 +1642,10 @@ impl Type {
     }
 
     pub fn is_fn(&self) -> bool {
-        matches!(&self.ty.value,
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::FnDef(..), .. }) |
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::FnPtr { .. }, .. })
+        matches!(
+            &self.ty.value,
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::FnDef(..), .. })
+                | Ty::Apply(ApplicationTy { ctor: TypeCtor::FnPtr { .. }, .. })
         )
     }