From 535f81a38775b56ad1e88cbb1369ae7d3f70d60d Mon Sep 17 00:00:00 2001
From: beder <jbeder@gmail.com>
Date: Tue, 13 Sep 2011 02:03:56 -0500
Subject: [PATCH] Added a convert<> specialization for YAML::_Null (so you can
 say node[YAML::Null])

---
 include/yaml-cpp/node/convert.h     | 15 +++++++++++++++
 include/yaml-cpp/node/detail/impl.h |  1 +
 test/new-api/spectests.cpp          | 15 +++++----------
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/include/yaml-cpp/node/convert.h b/include/yaml-cpp/node/convert.h
index d65e363..db3cb8c 100644
--- a/include/yaml-cpp/node/convert.h
+++ b/include/yaml-cpp/node/convert.h
@@ -8,6 +8,7 @@
 
 #include "yaml-cpp/node/node.h"
 #include "yaml-cpp/node/iterator.h"
+#include "yaml-cpp/null.h"
 #include <list>
 #include <map>
 #include <sstream>
@@ -30,6 +31,17 @@ namespace YAML
 		}
 	};
 	
+	template<>
+	struct convert<_Null> {
+		static Node encode(const _Null& /* rhs */) {
+			return Node();
+		}
+		
+		static bool decode(const Node& node, _Null& /* rhs */) {
+			return node.Type() == NodeType::Null;
+		}
+	};
+	
 #define YAML_DEFINE_CONVERT_STREAMABLE(type)\
 	template<>\
 	struct convert<type> {\
@@ -66,6 +78,7 @@ namespace YAML
 	
 #undef YAML_DEFINE_CONVERT_STREAMABLE
 
+	// std::map
 	template<typename K, typename V>
 	struct convert<std::map<K, V> > {
 		static Node encode(const std::map<K, V>& rhs) {
@@ -86,6 +99,7 @@ namespace YAML
 		}
 	};
 	
+	// std::vector
 	template<typename T>
 	struct convert<std::vector<T> > {
 		static Node encode(const std::vector<T>& rhs) {
@@ -106,6 +120,7 @@ namespace YAML
 		}
 	};
 	
+	// std::list
 	template<typename T>
 	struct convert<std::list<T> > {
 		static Node encode(const std::list<T>& rhs) {
diff --git a/include/yaml-cpp/node/detail/impl.h b/include/yaml-cpp/node/detail/impl.h
index eded94b..63800ca 100644
--- a/include/yaml-cpp/node/detail/impl.h
+++ b/include/yaml-cpp/node/detail/impl.h
@@ -132,6 +132,7 @@ namespace YAML
 		inline node& node_data::convert_to_node(const T& rhs, shared_memory_holder pMemory)
 		{
 			Node value = convert<T>::encode(rhs);
+			value.EnsureNodeExists();
 			pMemory->merge(*value.m_pMemory);
 			return *value.m_pNode;
 		}
diff --git a/test/new-api/spectests.cpp b/test/new-api/spectests.cpp
index 48e0384..5488f39 100644
--- a/test/new-api/spectests.cpp
+++ b/test/new-api/spectests.cpp
@@ -558,8 +558,7 @@ namespace Test
 			YAML::Node doc = YAML::Parse(ex7_3);
 			YAML_ASSERT(doc.size() == 2);
 			YAML_ASSERT(doc["foo"].Type() == YAML::NodeType::Null);
-//			YAML_ASSERT(doc[YAML::as<.as<std::string>() == "bar");
-			return "  null as a key not implemented";
+			YAML_ASSERT(doc[YAML::Null].as<std::string>() == "bar");
 			return true;
 		}
 		
@@ -692,8 +691,7 @@ namespace Test
 			YAML_ASSERT(doc.size() == 3);
 			YAML_ASSERT(doc["explicit"].as<std::string>() == "entry");
 			YAML_ASSERT(doc["implicit"].as<std::string>() == "entry");
-//			YAML_ASSERT(doc[YAML::as<.Type() == YAML::NodeType::Null);
-			return "  null as a key not implemented";
+			YAML_ASSERT(doc[YAML::Null].Type() == YAML::NodeType::Null);
 			return true;
 		}
 		
@@ -704,8 +702,7 @@ namespace Test
 			YAML_ASSERT(doc["unquoted"].as<std::string>() == "separate");
 			YAML_ASSERT(doc["http://foo.com"].Type() == YAML::NodeType::Null);
 			YAML_ASSERT(doc["omitted value"].Type() == YAML::NodeType::Null);
-//			YAML_ASSERT(doc[YAML::as<.as<std::string>() == "omitted key");
-			return "  null as a key not implemented";
+			YAML_ASSERT(doc[YAML::Null].as<std::string>() == "omitted key");
 			return true;
 		}
 		
@@ -746,8 +743,7 @@ namespace Test
 			YAML_ASSERT(doc[0][0]["YAML"].as<std::string>() == "separate");
 			YAML_ASSERT(doc[1].size() == 1);
 			YAML_ASSERT(doc[1][0].size() == 1);
-//			YAML_ASSERT(doc[1][0][YAML::as<.as<std::string>() == "empty key entry");
-			return "  null as a key not implemented";
+			YAML_ASSERT(doc[1][0][YAML::Null].as<std::string>() == "empty key entry");
 			YAML_ASSERT(doc[2].size() == 1);
 			YAML_ASSERT(doc[2][0].size() == 1);
 			
@@ -989,8 +985,7 @@ namespace Test
 			YAML::Node doc = YAML::Parse(ex8_18);
 			YAML_ASSERT(doc.size() == 3);
 			YAML_ASSERT(doc["plain key"].as<std::string>() == "in-line value");
-//			YAML_ASSERT(doc[YAML::Null].Type() == YAML::NodeType::Null);
-			return "  null not implemented as key";
+			YAML_ASSERT(doc[YAML::Null].Type() == YAML::NodeType::Null);
 			YAML_ASSERT(doc["quoted key"].size() == 1);
 			YAML_ASSERT(doc["quoted key"][0].as<std::string>() == "entry");
 			return true;