rustdoc: Turn the noise down on implemented traits

This commit removes the inherited documentation from type pages. This generally
just clutters up the page when you can click through to the trait itself to get
all the meaty documentation.

Closes #11991

src/librustdoc/html/render.rs

@@ -1619,54 +1619,24 @@ fn render_impl(w: &mut Writer, i: &clean::Impl,
         None => {}
     }
 
-    fn docmeth(w: &mut Writer, item: &clean::Item) -> io::IoResult<bool> {
+    fn docmeth(w: &mut Writer, item: &clean::Item,
+               dox: bool) -> io::IoResult<()> {
         try!(write!(w, "<h4 id='method.{}' class='method'><code>",
                       *item.name.get_ref()));
         try!(render_method(w, item));
         try!(write!(w, "</code></h4>\n"));
         match item.doc_value() {
-            Some(s) => {
+            Some(s) if dox => {
                 try!(write!(w, "<div class='docblock'>{}</div>", Markdown(s)));
-                Ok(true)
+                Ok(())
             }
-            None => Ok(false)
+            Some(..) | None => Ok(())
         }
     }
 
     try!(write!(w, "<div class='methods'>"));
     for meth in i.methods.iter() {
-        if try!(docmeth(w, meth)) {
-            continue
-        }
-
-        // No documentation? Attempt to slurp in the trait's documentation
-        let trait_id = match trait_id {
-            None => continue,
-            Some(id) => id,
-        };
-        try!(local_data::get(cache_key, |cache| {
-            let cache = cache.unwrap();
-            match cache.traits.find(&trait_id) {
-                Some(t) => {
-                    let name = meth.name.clone();
-                    match t.methods.iter().find(|t| t.item().name == name) {
-                        Some(method) => {
-                            match method.item().doc_value() {
-                                Some(s) => {
-                                    try!(write!(w,
-                                                  "<div class='docblock'>{}</div>",
-                                                  Markdown(s)));
-                                }
-                                None => {}
-                            }
-                        }
-                        None => {}
-                    }
-                }
-                None => {}
-            }
-            Ok(())
-        }))
+        try!(docmeth(w, meth, true));
     }
 
     // If we've implemented a trait, then also emit documentation for all
@@ -1685,7 +1655,7 @@ fn render_impl(w: &mut Writer, i: &clean::Impl,
                                 None => {}
                             }
 
-                            try!(docmeth(w, method.item()));
+                            try!(docmeth(w, method.item(), false));
                         }
                     }
                     None => {}