diff --git a/TinySTL/Deque.h b/TinySTL/Deque.h
index b8eb065..4bc410c 100644
--- a/TinySTL/Deque.h
+++ b/TinySTL/Deque.h
@@ -1,7 +1,11 @@
 #ifndef _DEQUE_H_
 #define _DEQUE_H_
 
-namespace TinySTL{
+#include "Allocator.h"
 
+namespace TinySTL{
+	//class of deque
+	template<class T, class Alloc = TinySTL::allocator<T>>
+	class deque{};
 }
 #endif
\ No newline at end of file
diff --git a/TinySTL/Functional.h b/TinySTL/Functional.h
new file mode 100644
index 0000000..85a86ee
--- /dev/null
+++ b/TinySTL/Functional.h
@@ -0,0 +1,17 @@
+#ifndef _FUNCTIONAL_H_
+#define _FUNCTIONAL_H_
+
+namespace TinySTL{
+	//********** [less] ****************
+	template<class T>
+	struct less{
+		typedef T first_argument_type;
+		typedef T second_argument_type;
+		typedef bool result_type;
+
+		result_type operator()(const first_argument_type& x, const second_argument_type& y){
+			return x < y;
+		}
+	};
+}
+#endif
\ No newline at end of file
diff --git a/TinySTL/Stack.h b/TinySTL/Stack.h
index c26b3f3..560756a 100644
--- a/TinySTL/Stack.h
+++ b/TinySTL/Stack.h
@@ -1,7 +1,11 @@
 #ifndef _STACK_H_
 #define _STACK_H_
 
-namespace TinySTL{
+#include "Deque.h"
 
+namespace TinySTL{
+	//class of stack
+	template<class T, class Container = TinySTL::deque<T>>
+	class stack{};
 }
 #endif
\ No newline at end of file