3 files changed, 29 insertions, 9 deletions

diff --git a/crates/ra_hir_def/src/item_tree.rs b/crates/ra_hir_def/src/item_tree.rs
index 8c93e3adf..3e603bd55 100644
--- a/crates/ra_hir_def/src/item_tree.rs
+++ b/crates/ra_hir_def/src/item_tree.rs
@@ -5,6 +5,7 @@ mod lower;
 mod tests;
 
 use std::{
+    any::type_name,
     fmt::{self, Debug},
     hash::{Hash, Hasher},
     marker::PhantomData,
@@ -540,7 +541,7 @@ pub struct Enum {
     pub name: Name,
     pub visibility: RawVisibilityId,
     pub generic_params: GenericParamsId,
-    pub variants: Range<Idx<Variant>>,
+    pub variants: IdRange<Variant>,
     pub ast_id: FileAstId<ast::EnumDef>,
 }
 
@@ -698,7 +699,6 @@ pub struct Variant {
     pub fields: Fields,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct IdRange<T> {
     range: Range<u32>,
     _p: PhantomData<T>,
@@ -717,6 +717,26 @@ impl<T> Iterator for IdRange<T> {
     }
 }
 
+impl<T> fmt::Debug for IdRange<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple(&format!("IdRange::<{}>", type_name::<T>())).field(&self.range).finish()
+    }
+}
+
+impl<T> Clone for IdRange<T> {
+    fn clone(&self) -> Self {
+        Self { range: self.range.clone(), _p: PhantomData }
+    }
+}
+
+impl<T> PartialEq for IdRange<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.range == other.range
+    }
+}
+
+impl<T> Eq for IdRange<T> {}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Fields {
     Record(IdRange<Field>),
diff --git a/crates/ra_hir_def/src/item_tree/lower.rs b/crates/ra_hir_def/src/item_tree/lower.rs
index 93e8cc0c8..5149dd141 100644
--- a/crates/ra_hir_def/src/item_tree/lower.rs
+++ b/crates/ra_hir_def/src/item_tree/lower.rs
@@ -257,14 +257,14 @@ impl Ctx {
         let generic_params = self.lower_generic_params(GenericsOwner::Enum, enum_);
         let variants = match &enum_.variant_list() {
             Some(variant_list) => self.lower_variants(variant_list),
-            None => self.next_variant_idx()..self.next_variant_idx(),
+            None => IdRange::new(self.next_variant_idx()..self.next_variant_idx()),
         };
         let ast_id = self.source_ast_id_map.ast_id(enum_);
         let res = Enum { name, visibility, generic_params, variants, ast_id };
         Some(id(self.data().enums.alloc(res)))
     }
 
-    fn lower_variants(&mut self, variants: &ast::EnumVariantList) -> Range<Idx<Variant>> {
+    fn lower_variants(&mut self, variants: &ast::EnumVariantList) -> IdRange<Variant> {
         let start = self.next_variant_idx();
         for variant in variants.variants() {
             if let Some(data) = self.lower_variant(&variant) {
@@ -273,7 +273,7 @@ impl Ctx {
             }
         }
         let end = self.next_variant_idx();
-        start..end
+        IdRange::new(start..end)
     }
 
     fn lower_variant(&mut self, variant: &ast::EnumVariant) -> Option<Variant> {
diff --git a/crates/ra_hir_def/src/item_tree/tests.rs b/crates/ra_hir_def/src/item_tree/tests.rs
index 18df42050..08559fb92 100644
--- a/crates/ra_hir_def/src/item_tree/tests.rs
+++ b/crates/ra_hir_def/src/item_tree/tests.rs
@@ -237,13 +237,13 @@ Trait { name: Name(Text("Tr")), visibility: RawVisibilityId("pub(self)"), generi
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct0"))] }, input: None }]) }]
 Struct { name: Name(Text("Struct0")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(1), fields: Unit, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(3), kind: Unit }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct1"))] }, input: None }]) }]
-Struct { name: Name(Text("Struct1")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(2), fields: Tuple(FieldIds { range: 0..1 }), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(4), kind: Tuple }
+Struct { name: Name(Text("Struct1")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(2), fields: Tuple(IdRange::<ra_hir_def::item_tree::Field>(0..1)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(4), kind: Tuple }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct2"))] }, input: None }]) }]
-Struct { name: Name(Text("Struct2")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(3), fields: Record(FieldIds { range: 1..2 }), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(5), kind: Record }
+Struct { name: Name(Text("Struct2")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(3), fields: Record(IdRange::<ra_hir_def::item_tree::Field>(1..2)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(5), kind: Record }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("en"))] }, input: None }]) }]
-Enum { name: Name(Text("En")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), variants: Idx::<Variant>(0)..Idx::<Variant>(1), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::EnumDef>(6) }
+Enum { name: Name(Text("En")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), variants: IdRange::<ra_hir_def::item_tree::Variant>(0..1), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::EnumDef>(6) }
 #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("un"))] }, input: None }]) }]
-Union { name: Name(Text("Un")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), fields: Record(FieldIds { range: 3..4 }), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::UnionDef>(7) }
+Union { name: Name(Text("Un")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), fields: Record(IdRange::<ra_hir_def::item_tree::Field>(3..4)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::UnionDef>(7) }
     "###);
 }