From 7542e041518f5ed973b5276ab4d05c8e25da11b1 Mon Sep 17 00:00:00 2001
From: Robert Haschke <rhaschke@techfak.uni-bielefeld.de>
Date: Sat, 17 Mar 2018 17:58:55 +0100
Subject: [PATCH] make alias assignment explicit

---
 include/yaml-cpp/node/impl.h | 11 ++++++-----
 include/yaml-cpp/node/node.h | 10 ++++++++++
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/include/yaml-cpp/node/impl.h b/include/yaml-cpp/node/impl.h
index 20c487a..fdca084 100644
--- a/include/yaml-cpp/node/impl.h
+++ b/include/yaml-cpp/node/impl.h
@@ -239,11 +239,12 @@ inline void Node::Assign(char* rhs) {
 }
 
 inline Node& Node::operator=(const Node& rhs) {
-  if (!m_isValid || !rhs.m_isValid)
-    throw InvalidNode();
-  if (is(rhs))
-    return *this;
-  AssignNode(rhs);
+  AssignData(rhs);
+  return *this;
+}
+
+inline Node& Node::operator=(const NodeAlias& rhs) {
+  AssignNode(rhs.m_node);
   return *this;
 }
 
diff --git a/include/yaml-cpp/node/node.h b/include/yaml-cpp/node/node.h
index 1ded7d2..5d82368 100644
--- a/include/yaml-cpp/node/node.h
+++ b/include/yaml-cpp/node/node.h
@@ -26,6 +26,7 @@ struct iterator_value;
 }  // namespace YAML
 
 namespace YAML {
+class YAML_CPP_API NodeAlias;
 class YAML_CPP_API Node {
  public:
   friend class NodeBuilder;
@@ -81,6 +82,7 @@ class YAML_CPP_API Node {
   template <typename T>
   Node& operator=(const T& rhs);
   Node& operator=(const Node& rhs);
+  Node& operator=(const NodeAlias& rhs);
   void reset(const Node& rhs = Node());
 
   // size/iterator
@@ -134,6 +136,14 @@ class YAML_CPP_API Node {
   mutable detail::node* m_pNode;
 };
 
+class NodeAlias {
+  friend class Node;
+public:
+  NodeAlias(const Node& node) : m_node(node) {}
+private:
+  const Node& m_node;
+};
+
 YAML_CPP_API bool operator==(const Node& lhs, const Node& rhs);
 
 YAML_CPP_API Node Clone(const Node& node);