make impl_subject more readable

kylematsuda · kylematsuda · commit 8d5ee1a0729b · 2023-04-13T16:43:34.000-06:00
diff --git a/compiler/rustc_middle/src/hir/mod.rs b/compiler/rustc_middle/src/hir/mod.rs
@@ -105,12 +105,10 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn impl_subject(self, def_id: DefId) -> EarlyBinder<ImplSubject<'tcx>> {
-        EarlyBinder(
-            self.impl_trait_ref(def_id)
-                .map(|t| t.subst_identity())
-                .map(ImplSubject::Trait)
-                .unwrap_or_else(|| ImplSubject::Inherent(self.type_of(def_id).subst_identity())),
-        )
+        match self.impl_trait_ref(def_id) {
+            Some(t) => t.map_bound(ImplSubject::Trait),
+            None => self.type_of(def_id).map_bound(ImplSubject::Inherent),
+        }
     }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -105,12 +105,10 @@ impl<'tcx> TyCtxt<'tcx> {`
`105`	`105`	`}`
`106`	`106`
`107`	`107`	`pub fn impl_subject(self, def_id: DefId) -> EarlyBinder<ImplSubject<'tcx>> {`
`108`		`- EarlyBinder(`
`109`		`- self.impl_trait_ref(def_id)`
`110`		`- .map(\|t\| t.subst_identity())`
`111`		`- .map(ImplSubject::Trait)`
`112`		`- .unwrap_or_else(\|\| ImplSubject::Inherent(self.type_of(def_id).subst_identity())),`
`113`		`- )`
	`108`	`+ match self.impl_trait_ref(def_id) {`
	`109`	`+ Some(t) => t.map_bound(ImplSubject::Trait),`
	`110`	`+ None => self.type_of(def_id).map_bound(ImplSubject::Inherent),`
	`111`	`+ }`
`114`	`112`	`}`
`115`	`113`	`}`
`116`	`114`