rustdoc: use `collect()` instead of repeatedly pushing to bounds

[rust.git] / src / librustdoc / clean / mod.rs

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 5e81db363ee5c1668e5153650521b567c55def06..5e6f3070d0bb2359514501c16743122383401ac6 100644 (file)
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -956,7 +956,11 @@ fn clean_fn_decl_with_args<'tcx>(
     decl: &hir::FnDecl<'tcx>,
     args: Arguments,
 ) -> FnDecl {
-    FnDecl { inputs: args, output: decl.output.clean(cx), c_variadic: decl.c_variadic }
+    let output = match decl.output {
+        hir::FnRetTy::Return(typ) => Return(clean_ty(typ, cx)),
+        hir::FnRetTy::DefaultReturn(..) => DefaultReturn,
+    };
+    FnDecl { inputs: args, output, c_variadic: decl.c_variadic }
 }
 
 fn clean_fn_decl_from_did_and_sig<'tcx>(
@@ -991,27 +995,16 @@ fn clean_fn_decl_from_did_and_sig<'tcx>(
     }
 }
 
-impl<'tcx> Clean<'tcx, FnRetTy> for hir::FnRetTy<'tcx> {
-    fn clean(&self, cx: &mut DocContext<'tcx>) -> FnRetTy {
-        match *self {
-            Self::Return(typ) => Return(clean_ty(typ, cx)),
-            Self::DefaultReturn(..) => DefaultReturn,
-        }
-    }
-}
-
-impl<'tcx> Clean<'tcx, Path> for hir::TraitRef<'tcx> {
-    fn clean(&self, cx: &mut DocContext<'tcx>) -> Path {
-        let path = clean_path(self.path, cx);
-        register_res(cx, path.res);
-        path
-    }
+fn clean_trait_ref<'tcx>(trait_ref: &hir::TraitRef<'tcx>, cx: &mut DocContext<'tcx>) -> Path {
+    let path = clean_path(trait_ref.path, cx);
+    register_res(cx, path.res);
+    path
 }
 
 impl<'tcx> Clean<'tcx, PolyTrait> for hir::PolyTraitRef<'tcx> {
     fn clean(&self, cx: &mut DocContext<'tcx>) -> PolyTrait {
         PolyTrait {
-            trait_: self.trait_ref.clean(cx),
+            trait_: clean_trait_ref(&self.trait_ref, cx),
             generic_params: self
                 .bound_generic_params
                 .iter()
@@ -1624,9 +1617,10 @@ pub(crate) fn clean_middle_ty<'tcx>(
             // HACK: pick the first `did` as the `did` of the trait object. Someone
             // might want to implement "native" support for marker-trait-only
             // trait objects.
-            let mut dids = obj.principal_def_id().into_iter().chain(obj.auto_traits());
-            let did = dids
-                .next()
+            let mut dids = obj.auto_traits();
+            let did = obj
+                .principal_def_id()
+                .or_else(|| dids.next())
                 .unwrap_or_else(|| panic!("found trait object `{:?}` with no traits?", this));
             let substs = match obj.principal() {
                 Some(principal) => principal.skip_binder().substs,
@@ -1637,19 +1631,18 @@ pub(crate) fn clean_middle_ty<'tcx>(
             inline::record_extern_fqn(cx, did, ItemType::Trait);
 
             let lifetime = clean_middle_region(*reg);
-            let mut bounds = vec![];
-
-            for did in dids {
-                let empty = cx.tcx.intern_substs(&[]);
-                let path = external_path(cx, did, false, vec![], empty);
-                inline::record_extern_fqn(cx, did, ItemType::Trait);
-                let bound = PolyTrait { trait_: path, generic_params: Vec::new() };
-                bounds.push(bound);
-            }
+            let mut bounds = dids
+                .map(|did| {
+                    let empty = cx.tcx.intern_substs(&[]);
+                    let path = external_path(cx, did, false, vec![], empty);
+                    inline::record_extern_fqn(cx, did, ItemType::Trait);
+                    PolyTrait { trait_: path, generic_params: Vec::new() }
+                })
+                .collect::<Vec<_>>();
 
-            let mut bindings = vec![];
-            for pb in obj.projection_bounds() {
-                bindings.push(TypeBinding {
+            let bindings = obj
+                .projection_bounds()
+                .map(|pb| TypeBinding {
                     assoc: projection_to_path_segment(
                         pb.skip_binder()
                             .lift_to_tcx(cx.tcx)
@@ -1663,8 +1656,8 @@ pub(crate) fn clean_middle_ty<'tcx>(
                     kind: TypeBindingKind::Equality {
                         term: clean_middle_term(pb.skip_binder().term, cx),
                     },
-                });
-            }
+                })
+                .collect();
 
             let path = external_path(cx, did, false, bindings, substs);
             bounds.insert(0, PolyTrait { trait_: path, generic_params: Vec::new() });
@@ -2000,7 +1993,7 @@ fn clean_impl<'tcx>(
 ) -> Vec<Item> {
     let tcx = cx.tcx;
     let mut ret = Vec::new();
-    let trait_ = impl_.of_trait.as_ref().map(|t| t.clean(cx));
+    let trait_ = impl_.of_trait.as_ref().map(|t| clean_trait_ref(t, cx));
     let items =
         impl_.items.iter().map(|ii| tcx.hir().impl_item(ii.id).clean(cx)).collect::<Vec<_>>();
     let def_id = tcx.hir().local_def_id(hir_id);