Ensure method names in iface and impl items are unique

Closes #2114

Author: marijnh

src/rustc/middle/infer.rs

@@ -1341,10 +1341,6 @@ impl of combine for glb {
         ok(ty::mk_bot(self.infcx().tcx))
     }
 
-    fn c_regions(a: ty::region, _b: ty::region) -> cres<ty::region> {
-        ok(a) // FIXME
-    }
-
     fn c_mts(a: ty::mt, b: ty::mt) -> cres<ty::mt> {
         let tcx = self.infcx().tcx;
 

src/rustc/middle/resolve.rs

@@ -1727,13 +1727,21 @@ fn check_item(e: @env, i: @ast::item, &&x: (), v: vt<()>) {
     alt i.node {
       ast::item_fn(decl, ty_params, _) {
         check_fn(*e, i.span, decl);
-        ensure_unique(*e, i.span, typaram_names(ty_params), ident_id,
+        ensure_unique(*e, i.span, ty_params, {|tp| tp.ident},
                       "type parameter");
       }
       ast::item_enum(_, ty_params) {
-        ensure_unique(*e, i.span, typaram_names(ty_params), ident_id,
+        ensure_unique(*e, i.span, ty_params, {|tp| tp.ident},
                       "type parameter");
       }
+      ast::item_iface(_, methods) {
+        ensure_unique(*e, i.span, methods, {|m| m.ident},
+                      "method");
+      }
+      ast::item_impl(_, _, _, methods) {
+        ensure_unique(*e, i.span, methods, {|m| m.ident},
+                      "method");
+      }
       _ { }
     }
 }
@@ -1871,8 +1879,6 @@ fn add_name(ch: checker, sp: span, name: ident) {
     ch.seen += [name];
 }
 
-fn ident_id(&&i: ident) -> ident { ret i; }
-
 fn ensure_unique<T>(e: env, sp: span, elts: [T], id: fn(T) -> ident,
                     kind: str) {
     let ch = checker(e, kind);