diff --git a/src/space/space.cpp b/src/space/space.cpp
index f4157ad..a70dc0e 100644
--- a/src/space/space.cpp
+++ b/src/space/space.cpp
@@ -36,7 +36,6 @@
  */
 
 #include <wchar.h>
-#include <utility>
 #include "space.h"
 #include "utf8/utf8.h"
 #include "convert/convert.h"
@@ -81,8 +80,6 @@ Space & Space::operator=(Space && space)
 Space::~Space()
 {
 	remove_value();
-	remove_child_spaces();
-	remove_space_name();
 }
 
 
@@ -194,6 +191,54 @@ void Space::clear()
 
 
 
+size_t Space::str_size() const
+{
+	if( is_str() )
+	{
+		return value.value_string.size();
+	}
+
+	return 0;
+}
+
+
+size_t Space::wstr_size() const
+{
+	if( is_wstr() )
+	{
+		return value.value_wstring.size();
+	}
+
+	return 0;
+}
+
+
+size_t Space::object_size() const
+{
+	if( is_object() )
+	{
+		return value.value_object.size();
+	}
+
+	return 0;
+}
+
+
+size_t Space::table_size() const
+{
+	if( is_table() )
+	{
+		return value.value_table.size();
+	}
+
+	return 0;
+}
+
+
+
+
+
+
 void Space::set_null()
 {
 	initialize_value_null_if_needed();
@@ -678,21 +723,6 @@ Space & Space::add_empty_space(const std::wstring & field)
 
 
 
-Space & Space::add_child_space(const wchar_t * space_name)
-{
-	initialize_child_spaces_if_needed();
-
-	child_spaces->push_back(new Space());
-	Space * last_space = child_spaces->back();
-
-	last_space->initialize_space_name_if_needed();
-	last_space->name->append(space_name);
-
-	return *last_space;
-}
-
-
-
 bool Space::is_null() const
 {
 	return type == type_null;
@@ -1884,31 +1914,143 @@ bool Space::has_value(const wchar_t * field, const std::wstring & val) const
 
 
 
+const Space * Space::find_child_space_const(const wchar_t * name) const
+{
+	const TableType * child_table = find_child_space_table();
+
+	if( child_table )
+	{
+		for(const Space & space : *child_table)
+		{
+			if( space.is_equal(child_spaces_name, name) )
+			{
+				return &space;
+			}
+		}
+	}
+
+	return nullptr;
+}
+
+
+
+const Space * Space::find_child_space_const(size_t table_index) const
+{
+	const TableType * child_table = find_child_space_table();
+
+	if( child_table && table_index < child_table->size() )
+	{
+		return (*child_table)[table_index];
+	}
+
+	return nullptr;
+}
+
+
+
+Space::TableType * Space::find_child_space_table()
+{
+	return get_table(child_spaces_field_table_name);
+}
+
+
+const Space::TableType * Space::find_child_space_table() const
+{
+	return get_table(child_spaces_field_table_name);
+}
+
+
+bool Space::child_spaces_empty() const
+{
+	const TableType * child_table = find_child_space_table();
+
+	if( child_table )
+	{
+		return child_table->empty();
+	}
+
+	return true;
+}
+
+size_t Space::child_spaces_size() const
+{
+	const TableType * child_table = find_child_space_table();
+
+	if( child_table )
+	{
+		return child_table->size();
+	}
+
+	return 0;
+}
+
 
 Space * Space::find_child_space(const wchar_t * name)
 {
-	return find_child_space_generic(name);
+	return const_cast<Space*>(find_child_space_const(name));
 }
 
+
 Space * Space::find_child_space(const std::wstring & name)
 {
-	return find_child_space_generic(name);
+	return find_child_space(name.c_str());
 }
 
 
 const Space * Space::find_child_space(const wchar_t * name) const
 {
-	return find_child_space_generic(name);
+	return find_child_space_const(name);
 }
 
 
 const Space * Space::find_child_space(const std::wstring & name) const
 {
-	return find_child_space_generic(name);
+	return find_child_space(name.c_str());
 }
 
 
 
+Space * Space::find_child_space(size_t table_index)
+{
+	return const_cast<Space*>(find_child_space_const(table_index));
+}
+
+const Space * Space::find_child_space(size_t table_index) const
+{
+	return find_child_space_const(table_index);
+}
+
+
+Space & Space::add_child_space()
+{
+	initialize_child_spaces_if_needed();
+
+	TableType * child_table = find_child_space_table();
+	child_table->push_back(new Space());
+
+	return child_table->back();
+}
+
+
+Space & Space::add_child_space(const wchar_t * space_name)
+{
+	initialize_child_spaces_if_needed();
+
+	TableType * child_table = find_child_space_table();
+	child_table->push_back(new Space());
+	Space * last_space = child_table->back();
+	last_space->add(child_spaces_name, space_name);
+
+	return *last_space;
+}
+
+
+Space & Space::add_child_space(const std::wstring & space_name)
+{
+	return add_child_space(space_name.c_str());
+}
+
+
 Space & Space::find_add_child_space(const wchar_t * name)
 {
 	Space * space = find_child_space(name);
@@ -1928,19 +2070,62 @@ Space & Space::find_add_child_space(const std::wstring & name)
 }
 
 
+std::wstring * Space::find_child_space_name()
+{
+	return get_wstr(child_spaces_name);
+}
+
+
+const std::wstring * Space::find_child_space_name() const
+{
+	return get_wstr(child_spaces_name);
+}
+
+
+std::wstring Space::get_child_space_name() const
+{
+	const std::wstring * name = find_child_space_name();
+
+	if( name )
+	{
+		return *name;
+	}
+	else
+	{
+		return std::wstring();
+	}
+}
+
+
+
+bool Space::is_child_space_name(const wchar_t * name) const
+{
+	return is_equal(child_spaces_name, name);
+}
+
+
+bool Space::is_child_space_name(const std::wstring & name) const
+{
+	return is_equal(child_spaces_name, name.c_str());
+}
+
+
+
+
 void Space::remove_child_space(const wchar_t * name)
 {
-	if( child_spaces )
-	{
-		for(size_t i=0 ; i<child_spaces->size() ; )
-		{
-			Space * child = (*child_spaces)[i];
+	TableType * child_table = find_child_space_table();
 
-			if( child->name && (*child->name) == name )
+	if( child_table )
+	{
+		for(size_t i=0 ; i<child_table->size() ; )
+		{
+			Space * child = (*child_table)[i];
+
+			if( child->is_equal(child_spaces_name, name) )
 			{
 				delete child;
-				child = nullptr;
-				child_spaces->erase(child_spaces->begin() + i);
+				child_table->erase(child_table->begin() + i);
 			}
 			else
 			{
@@ -1958,13 +2143,13 @@ void Space::remove_child_space(const std::wstring & name)
 
 void Space::remove_child_space(size_t index)
 {
-	if( child_spaces && index < child_spaces->size() )
-	{
-		Space * child = (*child_spaces)[index];
-		delete child;
-		child = nullptr;
+	TableType * child_table = find_child_space_table();
 
-		child_spaces->erase(child_spaces->begin() + index);
+	if( child_table && index < child_table->size() )
+	{
+		Space * child = (*child_table)[index];
+		delete child;
+		child_table->erase(child_table->begin() + index);
 	}
 }
 
@@ -2022,46 +2207,10 @@ void Space::copy_value_from(const Space & space)
 }
 
 
-void Space::copy_child_spaces_from(const Space & space)
-{
-	if( space.child_spaces )
-	{
-		initialize_child_spaces_if_needed();
-		child_spaces->clear();
-
-		for(size_t i = 0 ; i < space.child_spaces->size() ; ++i)
-		{
-			child_spaces->push_back(new Space((*space.child_spaces)[i]));
-		}
-	}
-	else
-	if( child_spaces )
-	{
-		remove_child_spaces();
-	}
-}
-
-
-void Space::copy_space_name_from(const Space & space)
-{
-	if( space.name )
-	{
-		initialize_space_name_if_needed();
-		*name = *space.name;
-	}
-	else
-	if( name )
-	{
-		remove_space_name();
-	}
-}
-
 
 void Space::copy_from(const Space & space)
 {
 	copy_value_from(space);
-	copy_child_spaces_from(space);
-	copy_space_name_from(space);
 }
 
 
@@ -2126,9 +2275,6 @@ void Space::move_from(Space && space)
 {
 	move_value_from(std::move(space));
 	space.type = Type::type_null;
-
-	std::swap(child_spaces, space.child_spaces);
-	std::swap(name, space.name);
 }
 
 
@@ -2137,8 +2283,6 @@ void Space::move_from(Space && space)
 void Space::initialize()
 {
 	type = type_null;
-	child_spaces = nullptr;
-	name = nullptr;
 }
 
 void Space::initialize_value_null_if_needed()
@@ -2300,18 +2444,17 @@ void Space::initialize_value_table_if_needed(TableType && tab)
 
 void Space::initialize_child_spaces_if_needed()
 {
-	if( child_spaces == nullptr )
+	Space * child_spaces = get_object_field(child_spaces_field_table_name);
+
+	if( child_spaces )
 	{
-		child_spaces = new TableType();
+		if( !child_spaces->is_table() )
+			child_spaces->set_empty_table();
 	}
-}
-
-
-void Space::initialize_space_name_if_needed()
-{
-	if( name == nullptr )
+	else
 	{
-		name = new std::wstring();
+		Space & new_child_spaces = add_empty_space(child_spaces_field_table_name);
+		new_child_spaces.set_empty_table();
 	}
 }
 
@@ -2396,34 +2539,6 @@ void Space::remove_value_table()
 }
 
 
-void Space::remove_child_spaces()
-{
-	if( child_spaces )
-	{
-		for(size_t i = 0 ; i < child_spaces->size() ; ++i)
-		{
-			delete (*child_spaces)[i];
-			(*child_spaces)[i] = nullptr;
-		}
-
-		delete child_spaces;
-		child_spaces = nullptr;
-	}
-}
-
-void Space::remove_space_name()
-{
-	if( name )
-	{
-		delete name;
-		name = nullptr;
-	}
-}
-
-
-
 
 } // namespace
 
-
-
diff --git a/src/space/space.h b/src/space/space.h
index 96dea3b..8cba9f2 100644
--- a/src/space/space.h
+++ b/src/space/space.h
@@ -135,6 +135,9 @@ public:
 	typedef std::map<std::wstring, Space*> ObjectType;
 	typedef std::vector<Space*> TableType;
 
+	constexpr static const wchar_t * child_spaces_field_table_name = L"child_spaces";
+	constexpr static const wchar_t * child_spaces_name = L"name";
+
 	enum Escape
 	{
 		no_escape,
@@ -179,10 +182,6 @@ public:
 	Type type;
 	Value value;
 
-	std::wstring * name;
-	TableType * child_spaces;
-
-
 
 	Space();
 	Space(const Space & space);
@@ -211,6 +210,12 @@ public:
 
 	void clear();
 
+	size_t str_size() const;
+	size_t wstr_size() const;
+	size_t object_size() const;
+	size_t table_size() const;
+
+
 	// set a new value
 	void set_null();
 	void set_empty_string();
@@ -576,16 +581,35 @@ public:
 
 
 	// for child spaces (used only in Space format)
-	Space * find_child_space(const wchar_t * name);
-	Space * find_child_space(const std::wstring & name);
+	TableType *       find_child_space_table();
+	const TableType * find_child_space_table() const;
+
+	bool   child_spaces_empty() const;
+	size_t child_spaces_size() const;
+
+	Space *       find_child_space(const wchar_t * name);
+	Space *       find_child_space(const std::wstring & name);
 	const Space * find_child_space(const wchar_t * name) const;
 	const Space * find_child_space(const std::wstring & name) const;
 
+	Space *       find_child_space(size_t table_index);
+	const Space * find_child_space(size_t table_index) const;
+
+	Space & add_child_space();
 	Space & add_child_space(const wchar_t * space_name);
+	Space & add_child_space(const std::wstring & space_name);
 
 	Space & find_add_child_space(const wchar_t * name);
 	Space & find_add_child_space(const std::wstring & name);
 
+	std::wstring *       find_child_space_name();
+	const std::wstring * find_child_space_name() const;
+
+	std::wstring get_child_space_name() const;
+
+	bool is_child_space_name(const wchar_t * name) const;
+	bool is_child_space_name(const std::wstring & name) const;
+
 	void remove_child_space(const wchar_t * name);
 	void remove_child_space(const std::wstring & name);
 	void remove_child_space(size_t index);
@@ -739,44 +763,6 @@ protected:
 	}
 
 
-	template<typename ArgType>
-	Space * find_child_space_generic(const ArgType & name)
-	{
-		if( child_spaces )
-		{
-			for(size_t i = 0 ; i < child_spaces->size() ; ++i)
-			{
-				Space * space = (*child_spaces)[i];
-
-				if( space->name && *space->name == name )
-				{
-					return space;
-				}
-			}
-		}
-
-		return nullptr;
-	}
-
-
-	template<typename ArgType>
-	Space * find_child_space_generic(const ArgType & name) const
-	{
-		if( child_spaces )
-		{
-			for(size_t i = 0 ; i < child_spaces->size() ; ++i)
-			{
-				Space * space = (*child_spaces)[i];
-
-				if( space->name && *space->name == name )
-				{
-					return space;
-				}
-			}
-		}
-
-		return nullptr;
-	}
 
 
 	template<typename StreamType>
@@ -969,7 +955,7 @@ protected:
 		if( !is_main_object )
 		{
 			str  << '{';
-			print_if(pretty_print && (!value.value_object.empty() || (child_spaces && !child_spaces->empty())), str, '\n');
+			print_if(pretty_print && (!value.value_object.empty() || !child_spaces_empty()), str, '\n');
 		}
 
 		bool is_first = true;
@@ -1009,21 +995,25 @@ protected:
 	template<typename StreamType>
 	void serialize_child_spaces(StreamType & str, bool pretty_print, int level) const
 	{
-		if( child_spaces && !child_spaces->empty() )
+		const TableType * child_table = find_child_space_table();
+
+		if( child_table && !child_table->empty() )
 		{
 			print_if(pretty_print, str, '\n');
 
-			for(Space * child_space : *child_spaces)
+			for(Space * child_space : *child_table)
 			{
 				print_if(!pretty_print, str, ' ');
 
-				if( child_space->name && !child_space->name->empty() )
+				const std::wstring * name = child_space->get_wstr(child_spaces_name);
+
+				if( name && !name->empty() )
 				{
-					bool quote_field = should_field_be_quoted(*child_space->name);
+					bool quote_field = should_field_be_quoted(*name);
 
 					print_level(pretty_print, level, str);
 					print_if(quote_field, str, '"');
-					serialize_string_buffer(child_space->name->c_str(), str, Escape::escape_space);
+					serialize_string_buffer(name->c_str(), str, Escape::escape_space);
 					print_if(quote_field, str, '"');
 
 					str << ' ';
@@ -1287,8 +1277,6 @@ protected:
 
 
 	void copy_value_from(const Space & space);
-	void copy_child_spaces_from(const Space & space);
-	void copy_space_name_from(const Space & space);
 	void copy_from(const Space & space);
 
 	void copy_value_object(const Value & value_from);
@@ -1312,15 +1300,15 @@ protected:
 	void initialize_value_table_if_needed();
 	void initialize_value_table_if_needed(TableType && tab);
 	void initialize_child_spaces_if_needed();
-	void initialize_space_name_if_needed();
 
 	void remove_value();
 	void remove_value_string();
 	void remove_value_wstring();
 	void remove_value_object();
 	void remove_value_table();
-	void remove_child_spaces();
-	void remove_space_name();
+
+	const Space * find_child_space_const(const wchar_t * name) const;
+	const Space * find_child_space_const(size_t table_index) const;
 
 
 };