XPath: Implement move semantics support

xpath_query, xpath_node_set and xpath_variable_set are now moveable.

This is a nice performance optimization for variable/node sets, and enables
storing xpath_query in containers without using pointers (it's only possible
now since the query is not copyable).

2 files changed, 119 insertions, 13 deletions

diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index d98df3e..37c61bb 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -11096,6 +11096,20 @@ namespace pugi
 		}
 	}
 
+#if __cplusplus >= 201103
+	PUGI__FN void xpath_node_set::_move(xpath_node_set& rhs)
+	{
+		_type = rhs._type;
+		_storage = rhs._storage;
+		_begin = (rhs._begin == &rhs._storage) ? &_storage : rhs._begin;
+		_end = _begin + (rhs._end - rhs._begin);
+
+		rhs._type = type_unsorted;
+		rhs._begin = &rhs._storage;
+		rhs._end = rhs._begin;
+	}
+#endif
+
 	PUGI__FN xpath_node_set::xpath_node_set(): _type(type_unsorted), _begin(&_storage), _end(&_storage)
 	{
 	}
@@ -11125,6 +11139,25 @@ namespace pugi
 		return *this;
 	}
 
+#if __cplusplus >= 201103
+	PUGI__FN xpath_node_set::xpath_node_set(xpath_node_set&& rhs): _type(type_unsorted), _begin(&_storage), _end(&_storage)
+	{
+		_move(rhs);
+	}
+
+	PUGI__FN xpath_node_set& xpath_node_set::operator=(xpath_node_set&& rhs)
+	{
+		if (this == &rhs) return *this;
+
+		if (_begin != &_storage)
+			impl::xml_memory::deallocate(_begin);
+
+		_move(rhs);
+
+		return *this;
+	}
+#endif
+
 	PUGI__FN xpath_node_set::type_t xpath_node_set::type() const
 	{
 		return _type;
@@ -11286,18 +11319,7 @@ namespace pugi
 	PUGI__FN xpath_variable_set::~xpath_variable_set()
 	{
 		for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
-		{
-			xpath_variable* var = _data[i];
-
-			while (var)
-			{
-				xpath_variable* next = var->_next;
-
-				impl::delete_xpath_variable(var->_type, var);
-
-				var = next;
-			}
-		}
+			_destroy(_data[i]);
 	}
 
 	PUGI__FN xpath_variable_set::xpath_variable_set(const xpath_variable_set& rhs)
@@ -11317,6 +11339,30 @@ namespace pugi
 		return *this;
 	}
 
+#if __cplusplus >= 201103
+	PUGI__FN xpath_variable_set::xpath_variable_set(xpath_variable_set&& rhs)
+	{
+		for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
+		{
+			_data[i] = rhs._data[i];
+			rhs._data[i] = 0;
+		}
+	}
+
+	PUGI__FN xpath_variable_set& xpath_variable_set::operator=(xpath_variable_set&& rhs)
+	{
+		for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
+		{
+			_destroy(_data[i]);
+
+			_data[i] = rhs._data[i];
+			rhs._data[i] = 0;
+		}
+
+		return *this;
+	}
+#endif
+
 	PUGI__FN void xpath_variable_set::_assign(const xpath_variable_set& rhs)
 	{
 		xpath_variable_set temp;
@@ -11379,6 +11425,18 @@ namespace pugi
 		return true;
 	}
 
+	PUGI__FN void xpath_variable_set::_destroy(xpath_variable* var)
+	{
+		while (var)
+		{
+			xpath_variable* next = var->_next;
+
+			impl::delete_xpath_variable(var->_type, var);
+
+			var = next;
+		}
+	}
+
 	PUGI__FN xpath_variable* xpath_variable_set::add(const char_t* name, xpath_value_type type)
 	{
 		const size_t hash_size = sizeof(_data) / sizeof(_data[0]);
@@ -11464,12 +11522,37 @@ namespace pugi
 		}
 	}
 
+	PUGI__FN xpath_query::xpath_query(): _impl(0)
+	{
+	}
+
 	PUGI__FN xpath_query::~xpath_query()
 	{
 		if (_impl)
 			impl::xpath_query_impl::destroy(static_cast<impl::xpath_query_impl*>(_impl));
 	}
 
+#if __cplusplus >= 201103
+	PUGI__FN xpath_query::xpath_query(xpath_query&& rhs)
+	{
+		_impl = rhs._impl;
+		rhs._impl = 0;
+	}
+
+	xpath_query& xpath_query::operator=(xpath_query&& rhs)
+	{
+		if (this == &rhs) return *this;
+
+		if (_impl)
+			impl::xpath_query_impl::destroy(static_cast<impl::xpath_query_impl*>(_impl));
+
+		_impl = rhs._impl;
+		rhs._impl = 0;
+
+		return *this;
+	}
+#endif
+
 	PUGI__FN xpath_value_type xpath_query::return_type() const
 	{
 		if (!_impl) return xpath_type_none;
diff --git a/src/pugixml.hpp b/src/pugixml.hpp
index b8b8946..0f79fb7 100644
--- a/src/pugixml.hpp
+++ b/src/pugixml.hpp
@@ -65,7 +65,7 @@
 
 // If the platform is known to have long long support, enable long long functions
 #ifndef PUGIXML_HAS_LONG_LONG
-#	if defined(__cplusplus) && __cplusplus >= 201103
+#	if __cplusplus >= 201103
 #		define PUGIXML_HAS_LONG_LONG
 #	elif defined(_MSC_VER) && _MSC_VER >= 1400
 #		define PUGIXML_HAS_LONG_LONG
@@ -1081,6 +1081,7 @@ namespace pugi
 		xpath_variable* _find(const char_t* name) const;
 
 		static bool _clone(xpath_variable* var, xpath_variable** out_result);
+		static void _destroy(xpath_variable* var);
 
 	public:
 		// Default constructor/destructor
@@ -1091,6 +1092,12 @@ namespace pugi
 		xpath_variable_set(const xpath_variable_set& rhs);
 		xpath_variable_set& operator=(const xpath_variable_set& rhs);
 
+	#if __cplusplus >= 201103
+		// Move semantics support
+		xpath_variable_set(xpath_variable_set&& rhs);
+		xpath_variable_set& operator=(xpath_variable_set&& rhs);
+	#endif
+
 		// Add a new variable or get the existing one, if the types match
 		xpath_variable* add(const char_t* name, xpath_value_type type);
 
@@ -1123,9 +1130,18 @@ namespace pugi
 		// If PUGIXML_NO_EXCEPTIONS is not defined, throws xpath_exception on compilation errors.
 		explicit xpath_query(const char_t* query, xpath_variable_set* variables = 0);
 
+		// Constructor
+		xpath_query();
+
 		// Destructor
 		~xpath_query();
 
+	#if __cplusplus >= 201103
+		// Move semantics support
+		xpath_query(xpath_query&& rhs);
+		xpath_query& operator=(xpath_query&& rhs);
+	#endif
+
 		// Get query expression return type
 		xpath_value_type return_type() const;
 		
@@ -1261,6 +1277,12 @@ namespace pugi
 		xpath_node_set(const xpath_node_set& ns);
 		xpath_node_set& operator=(const xpath_node_set& ns);
 
+	#if __cplusplus >= 201103
+		// Move semantics support
+		xpath_node_set(xpath_node_set&& rhs);
+		xpath_node_set& operator=(xpath_node_set&& rhs);
+	#endif
+
 		// Get collection type
 		type_t type() const;
 		
@@ -1292,6 +1314,7 @@ namespace pugi
 		xpath_node* _end;
 
 		void _assign(const_iterator begin, const_iterator end, type_t type);
+		void _move(xpath_node_set& rhs);
 	};
 #endif