diff --git a/llvm/include/llvm/BinaryFormat/MsgPackDocument.h b/llvm/include/llvm/BinaryFormat/MsgPackDocument.h
--- a/llvm/include/llvm/BinaryFormat/MsgPackDocument.h
+++ b/llvm/include/llvm/BinaryFormat/MsgPackDocument.h
@@ -193,6 +193,18 @@
   /// not rely on S having a lifetime beyond this call. Tag is "" or a YAML tag.
   StringRef fromString(StringRef S, StringRef Tag = "");
 
+  /// Convenience assignment operators. This only works if the destination
+  /// DocNode has an associated Document, i.e. it was not constructed using the
+  /// default constructor. The string one does not copy, so the string must
+  /// remain valid for the lifetime of the Document. Use fromString to avoid
+  /// that restriction.
+  DocNode &operator=(StringRef Val);
+  DocNode &operator=(bool Val);
+  DocNode &operator=(int Val);
+  DocNode &operator=(unsigned Val);
+  DocNode &operator=(int64_t Val);
+  DocNode &operator=(uint64_t Val);
+
 private:
   // Private constructor setting KindAndDoc, used by methods in Document.
   DocNode(const KindAndDocument *KindAndDoc) : KindAndDoc(KindAndDoc) {}
@@ -217,8 +229,12 @@
   /// Member access. The string data must remain valid for the lifetime of the
   /// Document.
   DocNode &operator[](StringRef S);
-  /// Member access.
+  /// Member access, with convenience versions for an integer key.
   DocNode &operator[](DocNode Key);
+  DocNode &operator[](int Key);
+  DocNode &operator[](unsigned Key);
+  DocNode &operator[](int64_t Key);
+  DocNode &operator[](uint64_t Key);
 };
 
 /// A DocNode that is an array.
diff --git a/llvm/lib/BinaryFormat/MsgPackDocument.cpp b/llvm/lib/BinaryFormat/MsgPackDocument.cpp
--- a/llvm/lib/BinaryFormat/MsgPackDocument.cpp
+++ b/llvm/lib/BinaryFormat/MsgPackDocument.cpp
@@ -48,6 +48,20 @@
   return N;
 }
 
+/// Member access for MapDocNode for integer key.
+DocNode &MapDocNode::operator[](int Key) {
+  return (*this)[getDocument()->getNode(Key)];
+}
+DocNode &MapDocNode::operator[](unsigned Key) {
+  return (*this)[getDocument()->getNode(Key)];
+}
+DocNode &MapDocNode::operator[](int64_t Key) {
+  return (*this)[getDocument()->getNode(Key)];
+}
+DocNode &MapDocNode::operator[](uint64_t Key) {
+  return (*this)[getDocument()->getNode(Key)];
+}
+
 /// Array element access. This extends the array if necessary.
 DocNode &ArrayDocNode::operator[](size_t Index) {
   if (size() <= Index) {
@@ -57,6 +71,36 @@
   return (*Array)[Index];
 }
 
+// Convenience assignment operators. This only works if the destination
+// DocNode has an associated Document, i.e. it was not constructed using the
+// default constructor. The string one does not copy, so the string must
+// remain valid for the lifetime of the Document. Use fromString to avoid
+// that restriction.
+DocNode &DocNode::operator=(StringRef Val) {
+  *this = getDocument()->getNode(Val);
+  return *this;
+}
+DocNode &DocNode::operator=(bool Val) {
+  *this = getDocument()->getNode(Val);
+  return *this;
+}
+DocNode &DocNode::operator=(int Val) {
+  *this = getDocument()->getNode(Val);
+  return *this;
+}
+DocNode &DocNode::operator=(unsigned Val) {
+  *this = getDocument()->getNode(Val);
+  return *this;
+}
+DocNode &DocNode::operator=(int64_t Val) {
+  *this = getDocument()->getNode(Val);
+  return *this;
+}
+DocNode &DocNode::operator=(uint64_t Val) {
+  *this = getDocument()->getNode(Val);
+  return *this;
+}
+
 // A level in the document reading stack.
 struct StackLevel {
   StackLevel(DocNode Node, size_t Length, DocNode *MapEntry = nullptr)