2 files changed, 32 insertions, 16 deletions

diff --git a/crates/hir/src/display.rs b/crates/hir/src/display.rs
index 44cdcc296..81f0e04e5 100644
--- a/crates/hir/src/display.rs
+++ b/crates/hir/src/display.rs
@@ -12,8 +12,8 @@ use hir_ty::display::{
 use syntax::ast::{self, NameOwner};
 
 use crate::{
-    Const, ConstParam, Enum, Field, Function, HasVisibility, Module, Static, Struct, Substs, Trait,
-    Type, TypeAlias, TypeParam, Union, Variant,
+    Adt, Const, ConstParam, Enum, Field, Function, GenericParam, HasVisibility, LifetimeParam,
+    Module, Static, Struct, Substs, Trait, Type, TypeAlias, TypeParam, Union, Variant,
 };
 
 impl HirDisplay for Function {
@@ -120,6 +120,16 @@ impl HirDisplay for Function {
     }
 }
 
+impl HirDisplay for Adt {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        match self {
+            Adt::Struct(it) => it.hir_fmt(f),
+            Adt::Union(it) => it.hir_fmt(f),
+            Adt::Enum(it) => it.hir_fmt(f),
+        }
+    }
+}
+
 impl HirDisplay for Struct {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         write_visibility(self.module(f.db).id, self.visibility(f.db), f)?;
@@ -211,6 +221,16 @@ impl HirDisplay for Type {
     }
 }
 
+impl HirDisplay for GenericParam {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        match self {
+            GenericParam::TypeParam(it) => it.hir_fmt(f),
+            GenericParam::LifetimeParam(it) => it.hir_fmt(f),
+            GenericParam::ConstParam(it) => it.hir_fmt(f),
+        }
+    }
+}
+
 impl HirDisplay for TypeParam {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         write!(f, "{}", self.name(f.db))?;
@@ -224,6 +244,12 @@ impl HirDisplay for TypeParam {
     }
 }
 
+impl HirDisplay for LifetimeParam {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write!(f, "{}", self.name(f.db))
+    }
+}
+
 impl HirDisplay for ConstParam {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         write!(f, "const {}: ", self.name(f.db))?;
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 8d45b4875..325014622 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -1,6 +1,6 @@
 use either::Either;
 use hir::{
-    Adt, AsAssocItem, AssocItemContainer, GenericParam, HasAttrs, HasSource, HirDisplay, Module,
+    AsAssocItem, AssocItemContainer, GenericParam, HasAttrs, HasSource, HirDisplay, Module,
     ModuleDef, Semantics,
 };
 use ide_db::{
@@ -339,9 +339,7 @@ fn hover_for_definition(
         Definition::ModuleDef(it) => match it {
             ModuleDef::Module(it) => from_hir_fmt(db, it, mod_path),
             ModuleDef::Function(it) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Adt(Adt::Struct(it)) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Adt(Adt::Union(it)) => from_hir_fmt(db, it, mod_path),
-            ModuleDef::Adt(Adt::Enum(it)) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Adt(it) => from_hir_fmt(db, it, mod_path),
             ModuleDef::Variant(it) => from_hir_fmt(db, it, mod_path),
             ModuleDef::Const(it) => from_hir_fmt(db, it, mod_path),
             ModuleDef::Static(it) => from_hir_fmt(db, it, mod_path),
@@ -353,18 +351,10 @@ fn hover_for_definition(
         },
         Definition::Local(it) => hover_for_local(it, db),
         Definition::SelfType(impl_def) => {
-            impl_def.target_ty(db).as_adt().and_then(|adt| match adt {
-                Adt::Struct(it) => from_hir_fmt(db, it, mod_path),
-                Adt::Union(it) => from_hir_fmt(db, it, mod_path),
-                Adt::Enum(it) => from_hir_fmt(db, it, mod_path),
-            })
+            impl_def.target_ty(db).as_adt().and_then(|adt| from_hir_fmt(db, adt, mod_path))
         }
+        Definition::GenericParam(it) => from_hir_fmt(db, it, None),
         Definition::Label(it) => Some(Markup::fenced_block(&it.name(db))),
-        Definition::GenericParam(it) => match it {
-            GenericParam::TypeParam(it) => Some(Markup::fenced_block(&it.display(db))),
-            GenericParam::LifetimeParam(it) => Some(Markup::fenced_block(&it.name(db))),
-            GenericParam::ConstParam(it) => Some(Markup::fenced_block(&it.display(db))),
-        },
     };
 
     fn from_hir_fmt<D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>