Rollup merge of #34105 - ollie27:rustdoc_derived, r=alexcrichton

rustdoc: Remove Derived Implementations title

As far as I know whether a trait was derived or not does not change the
public API so there is no need to include this information in the docs.

This title currently just adds an extra divide in the list of trait
implementations which I don't think needs to be there.

3 files changed, 1 insertions, 23 deletions

diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 8ffbd6be418..8894b9732fe 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -432,7 +432,6 @@ pub fn build_impl<'a, 'tcx>(cx: &DocContext,
     ret.push(clean::Item {
         inner: clean::ImplItem(clean::Impl {
             unsafety: hir::Unsafety::Normal, // FIXME: this should be decoded
-            derived: clean::detect_derived(&attrs),
             provided_trait_methods: provided,
             trait_: trait_,
             for_: for_,
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 65902205312..139dedeb70f 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2239,14 +2239,9 @@ pub struct Impl {
     pub trait_: Option<Type>,
     pub for_: Type,
     pub items: Vec<Item>,
-    pub derived: bool,
     pub polarity: Option<ImplPolarity>,
 }
 
-fn detect_derived<M: AttrMetaMethods>(attrs: &[M]) -> bool {
-    attr::contains_name(attrs, "automatically_derived")
-}
-
 impl Clean<Vec<Item>> for doctree::Impl {
     fn clean(&self, cx: &DocContext) -> Vec<Item> {
         let mut ret = Vec::new();
@@ -2283,7 +2278,6 @@ impl Clean<Vec<Item>> for doctree::Impl {
                 trait_: trait_,
                 for_: self.for_.clean(cx),
                 items: items,
-                derived: detect_derived(&self.attrs),
                 polarity: Some(self.polarity.clean(cx)),
             }),
         });
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index f63d37b3403..21463527ab9 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -399,7 +399,6 @@ fn init_ids() -> HashMap<String, usize> {
      "methods",
      "deref-methods",
      "implementations",
-     "derived_implementations"
      ].into_iter().map(|id| (String::from(*id), 1)).collect()
 }
 
@@ -2524,25 +2523,11 @@ fn render_assoc_items(w: &mut fmt::Formatter,
         }
         write!(w, "<h2 id='implementations'>Trait \
                    Implementations</h2>")?;
-        let (derived, manual): (Vec<_>, Vec<&Impl>) = traits.iter().partition(|i| {
-            i.inner_impl().derived
-        });
-        for i in &manual {
+        for i in &traits {
             let did = i.trait_did().unwrap();
             let assoc_link = AssocItemLink::GotoSource(did, &i.inner_impl().provided_trait_methods);
             render_impl(w, cx, i, assoc_link, true, containing_item.stable_since())?;
         }
-        if !derived.is_empty() {
-            write!(w, "<h3 id='derived_implementations'>\
-                           Derived Implementations \
-                       </h3>")?;
-            for i in &derived {
-                let did = i.trait_did().unwrap();
-                let assoc_link = AssocItemLink::GotoSource(did,
-                                                           &i.inner_impl().provided_trait_methods);
-                render_impl(w, cx, i, assoc_link, true, containing_item.stable_since())?;
-            }
-        }
     }
     Ok(())
 }