clippy::useless_conversion

crates/hir_def/src/item_tree/pretty.rs

@@ -426,7 +426,7 @@ fn print_mod_item(&mut self, item: ModItem) {
                         w!(self, " {{");
                         self.indented(|this| {
                             for item in &**items {
-                                this.print_mod_item((*item).into());
+                                this.print_mod_item(*item);
                             }
                         });
                         wln!(self, "}}");

crates/hir_def/src/lib.rs

@@ -736,8 +736,7 @@ fn macro_call_as_call_id(
                 db.upcast(),
                 krate,
                 MacroCallKind::FnLike { ast_id: call.ast_id, fragment },
-            )
-            .into())
+            ))
     };
     Ok(res)
 }
@@ -765,8 +764,7 @@ fn derive_macro_as_call_id(
                 derive_name: last_segment.to_string(),
                 derive_attr_index: derive_attr.ast_index,
             },
-        )
-        .into();
+        );
     Ok(res)
 }
 
@@ -804,7 +802,6 @@ fn attr_macro_as_call_id(
                 attr_args: arg,
                 invoc_attr_index: macro_attr.id.ast_index,
             },
-        )
-        .into();
+        );
     Ok(res)
 }

crates/hir_def/src/test_db.rs

@@ -325,7 +325,7 @@ pub(crate) fn diagnostics(&self, cb: &mut dyn FnMut(FileRange, String)) {
                         for diag in source_map.diagnostics() {
                             let (ptr, message): (InFile<SyntaxNodePtr>, &str) = match diag {
                                 BodyDiagnostic::InactiveCode { node, .. } => {
-                                    (node.clone().map(|it| it.into()), "InactiveCode")
+                                    (node.clone().map(|it| it), "InactiveCode")
                                 }
                                 BodyDiagnostic::MacroError { node, message } => {
                                     (node.clone().map(|it| it.into()), message.as_str())

crates/hir_expand/src/builtin_derive.rs

@@ -325,7 +325,7 @@ fn expand_builtin_derive(ra_fixture: &str) -> String {
             },
         };
 
-        let id: MacroCallId = db.intern_macro(loc).into();
+        let id: MacroCallId = db.intern_macro(loc);
         let parsed = db.parse_or_expand(id.as_file()).unwrap();
 
         // FIXME text() for syntax nodes parsed from token tree looks weird

crates/hir_expand/src/builtin_macro.rs

@@ -430,7 +430,7 @@ fn include_expand(
 ) -> ExpandResult<Option<ExpandedEager>> {
     let res = (|| {
         let path = parse_string(tt)?;
-        let file_id = relative_file(db, arg_id.into(), &path, false)?;
+        let file_id = relative_file(db, arg_id, &path, false)?;
 
         let subtree = parse_to_token_tree(&db.file_text(file_id))
             .ok_or_else(|| mbe::ExpandError::ConversionError)?
@@ -480,7 +480,7 @@ fn include_str_expand(
     // it's unusual to `include_str!` a Rust file), but we can return an empty string.
     // Ideally, we'd be able to offer a precise expansion if the user asks for macro
     // expansion.
-    let file_id = match relative_file(db, arg_id.into(), &path, true) {
+    let file_id = match relative_file(db, arg_id, &path, true) {
         Ok(file_id) => file_id,
         Err(_) => {
             return ExpandResult::ok(Some(ExpandedEager::new(quote!(""))));
@@ -598,7 +598,7 @@ fn expand_builtin_macro(ra_fixture: &str) -> String {
                     },
                 };
 
-                let id: MacroCallId = db.intern_macro(loc).into();
+                let id: MacroCallId = db.intern_macro(loc);
                 id.as_file()
             }
             Either::Right(expander) => {
@@ -635,7 +635,7 @@ fn expand_builtin_macro(ra_fixture: &str) -> String {
                     kind: MacroCallKind::FnLike { ast_id: call_id, fragment },
                 };
 
-                let id: MacroCallId = db.intern_macro(loc).into();
+                let id: MacroCallId = db.intern_macro(loc);
                 id.as_file()
             }
         };

crates/hir_expand/src/db.rs

@@ -57,7 +57,7 @@ fn expand(
                 // We store the result in salsa db to prevent non-deterministic behavior in
                 // some proc-macro implementation
                 // See #4315 for details
-                db.expand_proc_macro(id.into()).into()
+                db.expand_proc_macro(id).into()
             }
         }
     }

crates/hir_expand/src/eager.rs

@@ -128,7 +128,7 @@ pub fn expand_eager_macro(
         }),
         kind: MacroCallKind::FnLike { ast_id: call_id, fragment: FragmentKind::Expr },
     });
-    let arg_file_id: MacroCallId = arg_id.into();
+    let arg_file_id: MacroCallId = arg_id;
 
     let parsed_args =
         diagnostic_sink.result(mbe::token_tree_to_syntax_node(&parsed_args, FragmentKind::Expr))?.0;
@@ -182,8 +182,7 @@ fn lazy_expand(
             db,
             krate,
             MacroCallKind::FnLike { ast_id: macro_call.with_value(ast_id), fragment },
-        )
-        .into();
+        );
 
     let err = db.macro_expand_error(id);
     let value = db.parse_or_expand(id.as_file()).map(|node| InFile::new(id.as_file(), node));
@@ -216,8 +215,7 @@ fn eager_macro_recur(
                     def,
                     macro_resolver,
                     diagnostic_sink,
-                )?
-                .into();
+                )?;
                 db.parse_or_expand(id.as_file())
                     .expect("successful macro expansion should be parseable")
                     .clone_for_update()

crates/hir_ty/src/builder.rs

@@ -202,7 +202,7 @@ pub fn build(self) -> <T as Fold<Interner>>::Result {
 
 impl TyBuilder<Binders<Ty>> {
     pub fn def_ty(db: &dyn HirDatabase, def: TyDefId) -> TyBuilder<Binders<Ty>> {
-        TyBuilder::subst_binders(db.ty(def.into()))
+        TyBuilder::subst_binders(db.ty(def))
     }
 
     pub fn impl_self_ty(db: &dyn HirDatabase, def: hir_def::ImplId) -> TyBuilder<Binders<Ty>> {

xtask/src/codegen/gen_lint_completions.rs

@@ -140,8 +140,7 @@ fn generate_descriptor_clippy(buf: &mut String, path: &Path) -> Result<()> {
                 .expect("should be prefixed by what it does")
                 .strip_suffix(suffix_to_strip)
                 .map(unescape)
-                .expect("should be suffixed by comma")
-                .into();
+                .expect("should be suffixed by comma");
         }
     }
     clippy_lints.sort_by(|lint, lint2| lint.id.cmp(&lint2.id));