auto merge of #18993 : nikomatsakis/rust/hrtb-5, r=pcwalton

Enough said.

Fixes #18639.

r? @pcwalton (or someone else?)

This is a [breaking-change]. In particular, several feature gates related to unboxed closures were consolidated into one (`overloaded_calls`, `unboxed_closure_sugar` => `unboxed_closures`). Otherwise, I think everything that worked before should still work. File a bug and cc @nikomatsakis if you find otherwise. :)

1 files changed, 14 insertions, 3 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 98479d65cbb..40c4ac9f8c0 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -1023,10 +1023,21 @@ impl<'a> Parser<'a> {
             self.parse_ty_bare_fn_or_ty_closure(lifetime_defs)
         } else if self.token == token::ModSep ||
                   self.token.is_ident() ||
-                  self.token.is_path() {
+                  self.token.is_path()
+        {
             let trait_ref = self.parse_trait_ref();
-            TyPolyTraitRef(P(PolyTraitRef { bound_lifetimes: lifetime_defs,
-                                            trait_ref: trait_ref }))
+            let poly_trait_ref = ast::PolyTraitRef { bound_lifetimes: lifetime_defs,
+                                                     trait_ref: trait_ref };
+            let other_bounds = if self.eat(&token::BinOp(token::Plus)) {
+                self.parse_ty_param_bounds()
+            } else {
+                OwnedSlice::empty()
+            };
+            let all_bounds =
+                Some(TraitTyParamBound(poly_trait_ref)).into_iter()
+                .chain(other_bounds.into_vec().into_iter())
+                .collect();
+            ast::TyPolyTraitRef(all_bounds)
         } else {
             self.parse_ty_closure(lifetime_defs)
         }