Use an enum to record polarity in clean::Impl

Author: camelid

src/librustdoc/clean/auto_trait.rs

@@ -76,17 +76,17 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
             new_generics
         });
 
-        let negative_polarity;
+        let polarity;
         let new_generics = match result {
             AutoTraitResult::PositiveImpl(new_generics) => {
-                negative_polarity = false;
+                polarity = ImplPolarity::Positive;
                 if discard_positive_impl {
                     return None;
                 }
                 new_generics
             }
             AutoTraitResult::NegativeImpl => {
-                negative_polarity = true;
+                polarity = ImplPolarity::Negative;
 
                 // For negative impls, we use the generic params, but *not* the predicates,
                 // from the original type. Otherwise, the displayed impl appears to be a
@@ -120,7 +120,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                 trait_: Some(trait_ref.clean(self.cx)),
                 for_: ty.clean(self.cx),
                 items: Vec::new(),
-                negative_polarity,
+                polarity,
                 kind: ImplKind::Auto,
             }),
             cfg: None,

src/librustdoc/clean/blanket_impl.rs

@@ -123,7 +123,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
                             .in_definition_order()
                             .collect::<Vec<_>>()
                             .clean(self.cx),
-                        negative_polarity: false,
+                        polarity: ImplPolarity::Positive,
                         kind: ImplKind::Blanket(box trait_ref.self_ty().clean(self.cx)),
                     }),
                     cfg: None,

src/librustdoc/clean/inline.rs

@@ -497,7 +497,7 @@ crate fn build_impl(
             trait_,
             for_,
             items: trait_items,
-            negative_polarity: polarity.clean(cx),
+            polarity: polarity.clean(cx),
             kind: ImplKind::Normal,
         }),
         box merged_attrs,

src/librustdoc/clean/mod.rs

@@ -1856,14 +1856,14 @@ impl Clean<Item> for hir::Variant<'_> {
     }
 }
 
-impl Clean<bool> for ty::ImplPolarity {
+impl Clean<ImplPolarity> for ty::ImplPolarity {
     /// Returns whether the impl has negative polarity.
-    fn clean(&self, _: &mut DocContext<'_>) -> bool {
+    fn clean(&self, _: &mut DocContext<'_>) -> ImplPolarity {
         match self {
-            &ty::ImplPolarity::Positive |
+            ty::ImplPolarity::Positive |
             // FIXME: do we want to do something else here?
-            &ty::ImplPolarity::Reservation => false,
-            &ty::ImplPolarity::Negative => true,
+            ty::ImplPolarity::Reservation => ImplPolarity::Positive,
+            ty::ImplPolarity::Negative => ImplPolarity::Negative,
         }
     }
 }
@@ -1894,7 +1894,7 @@ fn clean_impl(impl_: &hir::Impl<'_>, hir_id: hir::HirId, cx: &mut DocContext<'_>
             trait_,
             for_,
             items,
-            negative_polarity: tcx.impl_polarity(def_id).clean(cx),
+            polarity: tcx.impl_polarity(def_id).clean(cx),
             kind: ImplKind::Normal,
         });
         Item::from_hir_id_and_parts(hir_id, None, kind, cx)

src/librustdoc/clean/types.rs

@@ -2177,7 +2177,7 @@ crate struct Impl {
     crate trait_: Option<Path>,
     crate for_: Type,
     crate items: Vec<Item>,
-    crate negative_polarity: bool,
+    crate polarity: ImplPolarity,
     crate kind: ImplKind,
 }
 
@@ -2227,6 +2227,13 @@ impl ImplKind {
     }
 }
 
+// FIXME: remove this and use ty::ImplPolarity instead
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+crate enum ImplPolarity {
+    Positive,
+    Negative,
+}
+
 #[derive(Clone, Debug)]
 crate struct Import {
     crate kind: ImportKind,

src/librustdoc/html/format.rs

@@ -990,8 +990,9 @@ impl clean::Impl {
             }
 
             if let Some(ref ty) = self.trait_ {
-                if self.negative_polarity {
-                    write!(f, "!")?;
+                match self.polarity {
+                    clean::ImplPolarity::Positive => {}
+                    clean::ImplPolarity::Negative => write!(f, "!")?,
                 }
                 fmt::Display::fmt(&ty.print(cx), f)?;
                 write!(f, " for ")?;

src/librustdoc/html/render/mod.rs

@@ -2033,12 +2033,12 @@ fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
                             let i_display = format!("{:#}", i.print(cx));
                             let out = Escape(&i_display);
                             let encoded = small_url_encode(format!("{:#}", i.print(cx)));
-                            let generated = format!(
-                                "<a href=\"#impl-{}\">{}{}</a>",
-                                encoded,
-                                if it.inner_impl().negative_polarity { "!" } else { "" },
-                                out
-                            );
+                            let prefix = match it.inner_impl().polarity {
+                                clean::ImplPolarity::Positive => "",
+                                clean::ImplPolarity::Negative => "!",
+                            };
+                            let generated =
+                                format!("<a href=\"#impl-{}\">{}{}</a>", encoded, prefix, out);
                             if links.insert(generated.clone()) { Some(generated) } else { None }
                         } else {
                             None

src/librustdoc/json/conversions.rs

@@ -500,8 +500,7 @@ impl FromWithTcx<clean::Trait> for Trait {
 impl FromWithTcx<clean::Impl> for Impl {
     fn from_tcx(impl_: clean::Impl, tcx: TyCtxt<'_>) -> Self {
         let provided_trait_methods = impl_.provided_trait_methods(tcx);
-        let clean::Impl { unsafety, generics, trait_, for_, items, negative_polarity, kind } =
-            impl_;
+        let clean::Impl { unsafety, generics, trait_, for_, items, polarity, kind } = impl_;
         // FIXME: should `trait_` be a clean::Path equivalent in JSON?
         let trait_ = trait_.map(|path| {
             let did = path.def_id();
@@ -513,6 +512,10 @@ impl FromWithTcx<clean::Impl> for Impl {
             clean::ImplKind::Auto => (true, None),
             clean::ImplKind::Blanket(ty) => (false, Some(*ty)),
         };
+        let negative_polarity = match polarity {
+            clean::ImplPolarity::Positive => false,
+            clean::ImplPolarity::Negative => true,
+        };
         Impl {
             is_unsafe: unsafety == rustc_hir::Unsafety::Unsafe,
             generics: generics.into_tcx(tcx),