Index: llvm/include/llvm/Support/BinaryStreamArray.h
===================================================================
--- llvm/include/llvm/Support/BinaryStreamArray.h
+++ llvm/include/llvm/Support/BinaryStreamArray.h
@@ -192,12 +192,7 @@
     return false;
   }
 
-  const ValueType &operator*() const {
-    assert(Array && !HasError);
-    return ThisValue;
-  }
-
-  ValueType &operator*() {
+  ValueType &operator*() const {
     assert(Array && !HasError);
     return ThisValue;
   }
@@ -242,7 +237,7 @@
       *HadError = true;
   }
 
-  ValueType ThisValue;
+  mutable ValueType ThisValue;
   BinaryStreamRef IterRef;
   Extractor Extract;
   const ArrayType *Array{nullptr};