[DEV] add some fucntions on tree

etk/FlatTree.hpp

@@ -208,7 +208,7 @@ namespace etk {
 			};
 			#endif
 		private:
-			etk::Vector<const ememory::SharedPtr<etk::TreeNode<ETK_TREENODE_TYPE>>> m_data;
+			etk::Vector<ememory::SharedPtr<etk::TreeNode<ETK_TREENODE_TYPE>>> m_data;
 		public:
 			FlatTree() {
 				
@@ -217,6 +217,27 @@ namespace etk {
 				m_data.clear();
 				append(_root);
 			}
+			size_t size() const {
+				return m_data.size();
+			}
+			auto begin() const {
+				return m_data.begin();
+			}
+			auto begin() {
+				return m_data.begin();
+			}
+			auto end() const {
+				return m_data.end();
+			}
+			auto end() {
+				return m_data.end();
+			}
+			auto operator[] (size_t _pos) {
+				return m_data[_pos];
+			}
+			auto operator[] (size_t _pos) const {
+				return m_data[_pos];
+			}
 		private:
 			void append(const ememory::SharedPtr<etk::TreeNode<ETK_TREENODE_TYPE>>& _node) {
 				if (_node == null) {

etk/TreeNode.hpp

@@ -124,6 +124,13 @@ namespace etk {
 				}
 				return out;
 			}
+			size_t countToRoot() {
+				auto parent = m_parent.lock();
+				if (parent == null) {
+					return 0;
+				}
+				return parent->countToRoot() + 1;
+			}
 	};
 }