Auto merge of #22028 - nikomatsakis:issue-22019-caching, r=aturon

[rust.git] / src / librustc / middle / traits / select.rs

diff --git a/src/librustc/middle/traits/select.rs b/src/librustc/middle/traits/select.rs
index a04aa9c56071164151edd604779a116fffbec9b1..1c341df85cb9840e6f84c37d09c736b32457c015 100644 (file)
--- a/src/librustc/middle/traits/select.rs
+++ b/src/librustc/middle/traits/select.rs
@@ -756,7 +756,7 @@ fn should_update_candidate_cache(&mut self,
                                      -> bool
     {
         // In general, it's a good idea to cache results, even
-        // ambigious ones, to save us some trouble later. But we have
+        // ambiguous ones, to save us some trouble later. But we have
         // to be careful not to cache results that could be
         // invalidated later by advances in inference. Normally, this
         // is not an issue, because any inference variables whose
@@ -1254,7 +1254,7 @@ fn winnow_selection<'o>(&mut self,
     ///
     /// - The impl is conditional, in which case we may not have winnowed it out
     ///   because we don't know if the conditions apply, but the where clause is basically
-    ///   telling us taht there is some impl, though not necessarily the one we see.
+    ///   telling us that there is some impl, though not necessarily the one we see.
     ///
     /// In both cases we prefer to take the where clause, which is
     /// essentially harmless.  See issue #18453 for more details of
@@ -1316,25 +1316,6 @@ fn candidate_should_be_dropped_in_favor_of<'o>(&mut self,
                 // the where clauses are in scope.
                 true
             }
-            (&ParamCandidate(ref bound1), &ParamCandidate(ref bound2)) => {
-                self.infcx.probe(|_| {
-                    let bound1 =
-                        project::normalize_with_depth(self,
-                                                      stack.obligation.cause.clone(),
-                                                      stack.obligation.recursion_depth+1,
-                                                      bound1);
-                    let bound2 =
-                        project::normalize_with_depth(self,
-                                                      stack.obligation.cause.clone(),
-                                                      stack.obligation.recursion_depth+1,
-                                                      bound2);
-                    let origin =
-                        infer::RelateOutputImplTypes(stack.obligation.cause.span);
-                    self.infcx
-                        .sub_poly_trait_refs(false, origin, bound1.value, bound2.value)
-                        .is_ok()
-                })
-            }
             _ => {
                 false
             }