DenseMapIterator: Avoid explicitly declaring the copy ctor as this makes the copy...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231093 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/ADT/DenseMap.h b/include/llvm/ADT/DenseMap.h
index 1699ea3ea6af313151caa8e9e835bad23be93afa..d947ffaa7edf7ff0c362d59b2afea8573747577b 100644 (file)
--- a/include/llvm/ADT/DenseMap.h
+++ b/include/llvm/ADT/DenseMap.h
@@ -1008,11 +1008,13 @@ public:
     if (!NoAdvance) AdvancePastEmptyBuckets();
   }
 
-  // If IsConst is true this is a converting constructor from iterator to
-  // const_iterator and the default copy constructor is used.
-  // Otherwise this is a copy constructor for iterator.
+  // Converting ctor from non-const iterators to const iterators. SFINAE'd out
+  // for const iterator destinations so it doesn't end up as a user defined copy
+  // constructor.
+  template <bool IsConstSrc,
+            typename = typename std::enable_if<!IsConstSrc && IsConst>::type>
   DenseMapIterator(
-      const DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, false> &I)
+      const DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, IsConstSrc> &I)
       : Ptr(I.Ptr), End(I.End) {}
 
   reference operator*() const {