From a95baeafd6556cb2eba346b7877c46dc89a321ab Mon Sep 17 00:00:00 2001
From: Jesse Beder <jbeder+github@gmail.com>
Date: Wed, 7 Sep 2011 15:49:01 -0500
Subject: [PATCH] Implemented conversion for std::string, including a
 bypass-accessor to the scalar value

---
 include/yaml-cpp/value/detail/node.h      |  5 +++--
 include/yaml-cpp/value/detail/node_data.h |  2 +-
 include/yaml-cpp/value/detail/node_ref.h  |  1 +
 include/yaml-cpp/value/impl.h             | 13 +++++++++++++
 include/yaml-cpp/value/value.h            |  1 +
 src/value/convert.cpp                     | 17 +++++++++++++++++
 util/value.cpp                            |  5 +++++
 7 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 src/value/convert.cpp

diff --git a/include/yaml-cpp/value/detail/node.h b/include/yaml-cpp/value/detail/node.h
index 97b3c3e..2521df9 100644
--- a/include/yaml-cpp/value/detail/node.h
+++ b/include/yaml-cpp/value/detail/node.h
@@ -20,9 +20,10 @@ namespace YAML
 		public:
 			explicit node(shared_node_ref pRef): m_pRef(pRef) {}
 
-			ValueType::value type() const { return m_pRef->type(); }
-
 			bool is(const node& rhs) const { return m_pRef == rhs.m_pRef; }
+			ValueType::value type() const { return m_pRef->type(); }
+			
+			const std::string& scalar() const { return m_pRef->scalar(); }
 			
 			void set_ref(const node& rhs) { m_pRef = rhs.m_pRef; }
 			void set_data(const node& rhs) { m_pRef->set_data(*rhs.m_pRef); }
diff --git a/include/yaml-cpp/value/detail/node_data.h b/include/yaml-cpp/value/detail/node_data.h
index 7fe8405..db1a341 100644
--- a/include/yaml-cpp/value/detail/node_data.h
+++ b/include/yaml-cpp/value/detail/node_data.h
@@ -27,7 +27,7 @@ namespace YAML
 			void set_scalar(const std::string& scalar);
 			
 			ValueType::value type() const { return m_isDefined ? m_type : ValueType::Undefined; }
-			const std::string scalar() const { return m_scalar; }
+			const std::string& scalar() const { return m_scalar; }
 			
 			// indexing
 			template<typename Key> shared_node get(const Key& key, shared_memory_holder pMemory) const;
diff --git a/include/yaml-cpp/value/detail/node_ref.h b/include/yaml-cpp/value/detail/node_ref.h
index 6c34042..6c81569 100644
--- a/include/yaml-cpp/value/detail/node_ref.h
+++ b/include/yaml-cpp/value/detail/node_ref.h
@@ -21,6 +21,7 @@ namespace YAML
 			node_ref(): m_pData(new node_data) {}
 			
 			ValueType::value type() const { return m_pData->type(); }
+			const std::string& scalar() const { return m_pData->scalar(); }
 			
 			void set_data(const node_ref& rhs) { m_pData = rhs.m_pData; }
 			
diff --git a/include/yaml-cpp/value/impl.h b/include/yaml-cpp/value/impl.h
index c4625f8..00a58f2 100644
--- a/include/yaml-cpp/value/impl.h
+++ b/include/yaml-cpp/value/impl.h
@@ -56,6 +56,19 @@ namespace YAML
 		throw std::runtime_error("Unable to convert to type");
 	}
 	
+	template<>
+	inline const std::string Value::as() const
+	{
+		if(Type() != ValueType::Scalar)
+			throw std::runtime_error("Unable to convert to string, not a scalar");
+		return scalar();
+	}
+
+	inline const std::string& Value::scalar() const
+	{
+		return m_pNode->scalar();
+	}
+
 	// assignment
 	inline bool Value::is(const Value& rhs) const
 	{
diff --git a/include/yaml-cpp/value/value.h b/include/yaml-cpp/value/value.h
index 039dfe2..f0a53ba 100644
--- a/include/yaml-cpp/value/value.h
+++ b/include/yaml-cpp/value/value.h
@@ -29,6 +29,7 @@ namespace YAML
 		
 		// access
 		template<typename T> const T as() const;
+		const std::string& scalar() const;
 		
 		// assignment
 		bool is(const Value& rhs) const;
diff --git a/src/value/convert.cpp b/src/value/convert.cpp
new file mode 100644
index 0000000..8bfd9cb
--- /dev/null
+++ b/src/value/convert.cpp
@@ -0,0 +1,17 @@
+#include "yaml-cpp/value.h"
+
+namespace YAML
+{
+	template<>
+	Value convert(const std::string& rhs) {
+		return Value(rhs);
+	}
+	
+	template<>
+	bool convert(const Value& value, std::string& rhs) {
+		if(value.Type() != ValueType::Scalar)
+			return false;
+		rhs = value.scalar();
+		return true;
+	}
+}
diff --git a/util/value.cpp b/util/value.cpp
index e8f57a8..136ca45 100644
--- a/util/value.cpp
+++ b/util/value.cpp
@@ -4,6 +4,11 @@ int main()
 {
 	YAML::Value value;
 	value["key"] = "value";
+	std::cout << value["key"].as<std::string>() << "\n";
+	value["key"]["key"] = "value";
+	std::cout << value["key"]["key"].as<std::string>() << "\n";
+//	value[5] = "monkey";
+//	std::cout << value[5].as<std::string>() << "\n";
 	
 	return 0;
 }