From d8b9387ace8331ce1a61d496c8f3251ac1de6928 Mon Sep 17 00:00:00 2001
From: varkor <github@varkor.com>
Date: Mon, 18 Mar 2019 21:00:52 +0000
Subject: [PATCH] Take ConstValue::Placeholder into account in new locations

---
 src/librustc/ty/structural_impls.rs    | 4 +++-
 src/librustc_typeck/check/writeback.rs | 4 ++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/librustc/ty/structural_impls.rs b/src/librustc/ty/structural_impls.rs
index 3057c529ddf..504b939c5f2 100644
--- a/src/librustc/ty/structural_impls.rs
+++ b/src/librustc/ty/structural_impls.rs
@@ -1355,6 +1355,7 @@ fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F)
             // FIXME(const_generics): implement TypeFoldable for InferConst
             ConstValue::Infer(ic) => ConstValue::Infer(ic),
             ConstValue::Param(p) => ConstValue::Param(p.fold_with(folder)),
+            ConstValue::Placeholder(p) => ConstValue::Placeholder(p),
             ConstValue::Scalar(a) => ConstValue::Scalar(a),
             ConstValue::Slice(a, b) => ConstValue::Slice(a, b),
             ConstValue::Unevaluated(did, substs)
@@ -1366,8 +1367,9 @@ fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
         match *self {
             ConstValue::ByRef(..) => false,
             // FIXME(const_generics): implement TypeFoldable for InferConst
-            ConstValue::Infer(_ic) => false,
+            ConstValue::Infer(_) => false,
             ConstValue::Param(p) => p.visit_with(visitor),
+            ConstValue::Placeholder(_) => false,
             ConstValue::Scalar(_) => false,
             ConstValue::Slice(..) => false,
             ConstValue::Unevaluated(_, substs) => substs.visit_with(visitor),
diff --git a/src/librustc_typeck/check/writeback.rs b/src/librustc_typeck/check/writeback.rs
index f56ef1a0d0c..5d98cb568bd 100644
--- a/src/librustc_typeck/check/writeback.rs
+++ b/src/librustc_typeck/check/writeback.rs
@@ -11,7 +11,7 @@
 use rustc::ty::adjustment::{Adjust, Adjustment, PointerCast};
 use rustc::ty::fold::{BottomUpFolder, TypeFoldable, TypeFolder};
 use rustc::ty::subst::UnpackedKind;
-use rustc::ty::{self, Ty, TyCtxt, Const};
+use rustc::ty::{self, Ty, TyCtxt};
 use rustc::mir::interpret::ConstValue;
 use rustc::util::nodemap::DefIdSet;
 use rustc_data_structures::sync::Lrc;
@@ -579,7 +579,7 @@ fn visit_opaque_types(&mut self, span: Span) {
                                         // parameter from the existential type
                                         return self.tcx()
                                             .global_tcx()
-                                            .mk_const_param(param.index, param.name, ty);
+                                            .mk_const_param(param.index, param.name, ct.ty);
                                     }
                                 }
                             }