diff --git a/include/nana/basic_types.hpp b/include/nana/basic_types.hpp
index e990a681..4fb4385d 100644
--- a/include/nana/basic_types.hpp
+++ b/include/nana/basic_types.hpp
@@ -337,9 +337,9 @@ namespace nana
 		bool operator==(const color& other) const;
 		bool operator!=(const color& other) const;
 	private:
-		double r_;
-		double g_;
-		double b_;
+		double r_{ 0.0 };
+		double g_{ 0.0 };
+		double b_{ 0.0 };
 		double a_{ 0.0 };	//invisible
 	};
 
diff --git a/include/nana/detail/linux_X11/platform_spec.hpp b/include/nana/detail/linux_X11/platform_spec.hpp
index c8866d9d..12bb65c3 100644
--- a/include/nana/detail/linux_X11/platform_spec.hpp
+++ b/include/nana/detail/linux_X11/platform_spec.hpp
@@ -60,6 +60,8 @@ namespace detail
 
 	class charset_conv
 	{
+		charset_conv(const charset_conv&) = delete;
+		charset_conv& operator=(const charset_conv*) = delete;
 	public:
 		charset_conv(const char* tocode, const char* fromcode);
 		~charset_conv();
@@ -118,6 +120,9 @@ namespace detail
 		void update_color();
 		void update_text_color();
 	private:
+		drawable_impl_type(const drawable_impl_type&) = delete;
+		drawable_impl_type& operator=(const drawable_impl_type&) = delete;
+
 		unsigned current_color_{ 0xFFFFFF };
 		unsigned color_{ 0xFFFFFFFF };
 		unsigned text_color_{ 0xFFFFFFFF };
diff --git a/include/nana/gui/detail/general_events.hpp b/include/nana/gui/detail/general_events.hpp
index 29dae364..454b407f 100644
--- a/include/nana/gui/detail/general_events.hpp
+++ b/include/nana/gui/detail/general_events.hpp
@@ -429,7 +429,7 @@ namespace nana
 	private:
 		unsigned emitting_count_{ 0 };
 		bool deleted_flags_{ false };
-		std::unique_ptr<std::vector<std::unique_ptr<detail::docker_interface>>> dockers_;
+		std::unique_ptr<std::vector<std::unique_ptr<detail::docker_interface>>> dockers_{ nullptr };
 	};
  
 	struct arg_mouse
diff --git a/include/nana/gui/widgets/spinbox.hpp b/include/nana/gui/widgets/spinbox.hpp
index e3d28505..fd60f070 100644
--- a/include/nana/gui/widgets/spinbox.hpp
+++ b/include/nana/gui/widgets/spinbox.hpp
@@ -68,7 +68,7 @@ namespace nana
 			private:
 				implementation * const impl_;
 			};
-		};
+		}
 	}//end namespace drawerbase
 
 	/// Spinbox Widget
diff --git a/include/nana/gui/widgets/treebox.hpp b/include/nana/gui/widgets/treebox.hpp
index f0cc4cd1..487812ea 100644
--- a/include/nana/gui/widgets/treebox.hpp
+++ b/include/nana/gui/widgets/treebox.hpp
@@ -307,14 +307,14 @@ namespace nana
 				{
 					_m_value() = t;
 					return *this;
-				};
+				}
 
 				template<typename T>
 				item_proxy & value(T&& t)
 				{
 					_m_value() = std::move(t);
 					return *this;
-				};
+				}
 
 				// Undocumentated methods for internal use
 				trigger::node_type * _m_node() const;
diff --git a/include/nana/system/shared_wrapper.hpp b/include/nana/system/shared_wrapper.hpp
index b1737cc2..ab14997e 100644
--- a/include/nana/system/shared_wrapper.hpp
+++ b/include/nana/system/shared_wrapper.hpp
@@ -30,7 +30,7 @@ namespace system
 			typedef void*	module_t;
 			void* symbols(module_t handle, const char* symbol);
 
-		}; //end struct shared_helper
+		} //end namespace shared_helper
 	}//end namespace detail
 
 	class shared_wrapper
diff --git a/include/nana/unicode_bidi.hpp b/include/nana/unicode_bidi.hpp
index acd2b057..766edf46 100644
--- a/include/nana/unicode_bidi.hpp
+++ b/include/nana/unicode_bidi.hpp
@@ -60,7 +60,7 @@ namespace nana
 		void _m_resolve_weak_types();
 		void _m_resolve_neutral_types();
 		void _m_resolve_implicit_levels();
-		void _m_reordering_resolved_levels(const char_type*, std::vector<entity> & reordered);
+		void _m_reordering_resolved_levels(std::vector<entity> & reordered);
 		static bidi_category _m_bidi_category(bidi_char);
 		static bidi_char _m_char_dir(char_type);
 	private:
diff --git a/source/datetime.cpp b/source/datetime.cpp
index 4682c32c..849ec940 100644
--- a/source/datetime.cpp
+++ b/source/datetime.cpp
@@ -264,6 +264,7 @@ namespace nana
 		}
 
 		time::time()
+			: value_{}
 		{
 			struct tm t;
 			localtime(t);
diff --git a/source/detail/platform_spec_posix.cpp b/source/detail/platform_spec_posix.cpp
index 9713a0c9..accaeed2 100644
--- a/source/detail/platform_spec_posix.cpp
+++ b/source/detail/platform_spec_posix.cpp
@@ -432,13 +432,13 @@ namespace detail
 		platform_spec::instance().unlock_xlib();
 	}
 
-	int X11_error_handler(Display* disp, XErrorEvent* err)
+	int X11_error_handler(Display*, XErrorEvent* err)
 	{
 	    platform_spec::instance().error_code = err->error_code;
 		return 0;
 	}
 
-	int X11_fatal_handler(Display* disp)
+	int X11_fatal_handler(Display*)
 	{
 		return 0;
 	}
diff --git a/source/filesystem/filesystem.cpp b/source/filesystem/filesystem.cpp
index ead15a1a..69f467cf 100644
--- a/source/filesystem/filesystem.cpp
+++ b/source/filesystem/filesystem.cpp
@@ -813,6 +813,7 @@ namespace nana {	namespace experimental {	namespace filesystem
 
 			bool remove(const path& p, std::error_code & ec)
 			{
+				ec.clear();
 				auto stat = status(p);
 				if (stat.type() == file_type::directory)
 					return detail::rm_dir(p);
diff --git a/source/gui/detail/bedrock_posix.cpp b/source/gui/detail/bedrock_posix.cpp
index 052a61aa..a8fa2254 100644
--- a/source/gui/detail/bedrock_posix.cpp
+++ b/source/gui/detail/bedrock_posix.cpp
@@ -153,7 +153,7 @@ namespace detail
 		delete impl_;
 	}
 
-	void bedrock::map_thread_root_buffer(core_window_t*, bool forced, const rectangle*)
+	void bedrock::map_thread_root_buffer(core_window_t*, bool /*forced*/, const rectangle*)
 	{
 		//GUI in X11 is thread-independent, so no implementation.
 	}
@@ -366,7 +366,7 @@ namespace detail
 		return impl_->estore;
 	}
 
-	void bedrock::map_through_widgets(core_window_t* wd, native_drawable_type drawable)
+	void bedrock::map_through_widgets(core_window_t*, native_drawable_type)
 	{
 		//No implementation for Linux
 	}
@@ -523,7 +523,7 @@ namespace detail
 		}
 	}
 
-	void window_proc_for_packet(Display * display, nana::detail::msg_packet_tag& msg)
+	void window_proc_for_packet(Display * /*display*/, nana::detail::msg_packet_tag& msg)
 	{
 		static auto& brock = detail::bedrock::instance();
 
@@ -642,7 +642,7 @@ namespace detail
 		return wchar_t(keysym);
 	}
 
-	void window_proc_for_xevent(Display* display, XEvent& xevent)
+	void window_proc_for_xevent(Display* /*display*/, XEvent& xevent)
 	{
 		typedef detail::bedrock::core_window_t core_window_t;
 
@@ -1308,7 +1308,7 @@ namespace detail
 		}
 	}
 
-	void bedrock::pump_event(window modal_window, bool is_modal)
+	void bedrock::pump_event(window modal_window, bool /*is_modal*/)
 	{
 		thread_context * context = open_thread_context();
 		if(0 == context->window_count)
diff --git a/source/gui/detail/native_window_interface.cpp b/source/gui/detail/native_window_interface.cpp
index ea84c1d3..258f3d1c 100644
--- a/source/gui/detail/native_window_interface.cpp
+++ b/source/gui/detail/native_window_interface.cpp
@@ -173,6 +173,8 @@ namespace nana{
 									mi.rcWork.right - mi.rcWork.left, mi.rcWork.bottom - mi.rcWork.top);
 				}
 			}
+#else
+			static_cast<void>(pos); //eliminate unused parameter compiler warning.
 #endif
 			return rectangle{ primary_monitor_size() };
 		}
@@ -547,6 +549,8 @@ namespace nana{
 			activate_window(reinterpret_cast<native_window_type>(
 								::GetWindow(reinterpret_cast<HWND>(wd), GW_OWNER)
 							));
+#else
+			static_cast<void>(wd);	//eliminate unused parameter compiler warning.
 #endif
 		}
 
@@ -565,6 +569,8 @@ namespace nana{
 				else
 					::PostMessage(native_wd, nana::detail::messages::async_activate, 0, 0);
 			}
+#else
+			static_cast<void>(wd);	//eliminate unused parameter compiler warning.
 #endif
 		}
 
@@ -640,6 +646,7 @@ namespace nana{
 
 				::XFlush(disp);
 			}
+			static_cast<void>(active);	//eliminate unused parameter compiler warning.
 #endif
 		}
 
@@ -715,6 +722,7 @@ namespace nana{
 #if defined(NANA_WINDOWS)
 			::InvalidateRect(reinterpret_cast<HWND>(wd), nullptr, true);
 #elif defined(NANA_X11)
+			static_cast<void>(wd); //eliminate unused parameter compiler warning.
 #endif
 		}
 
@@ -963,6 +971,7 @@ namespace nana{
 			::SetWindowPos(native_wd, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE);
 			::AttachThreadInput(::GetCurrentThreadId(), fg_tid, FALSE);
 #else
+			static_cast<void>(activated); //eliminate unused parameter compiler warning.
 			set_window_z_order(wd, nullptr, z_order_action::top);
 #endif
 		}
@@ -1414,6 +1423,11 @@ namespace nana{
 				if(static_cast<unsigned>(y) > sz.height + ext_height)
 					sz.height = static_cast<unsigned>(y);
 			}
+#else
+			//eliminate unused parameter compiler warning.
+			static_cast<void>(ext_width);
+			static_cast<void>(ext_height);
+			static_cast<void>(true_for_max);
 #endif
 			return sz;
 		}
diff --git a/source/gui/detail/window_layout.cpp b/source/gui/detail/window_layout.cpp
index f44be0a6..d2556323 100644
--- a/source/gui/detail/window_layout.cpp
+++ b/source/gui/detail/window_layout.cpp
@@ -357,7 +357,7 @@ namespace nana
 
 			//_m_notify_glasses
 			//@brief:	Notify the glass windows that are overlapped with the specified vis_rect
-			void window_layout::_m_notify_glasses(core_window_t* const sigwd, const nana::rectangle& r_visual)
+			void window_layout::_m_notify_glasses(core_window_t* const sigwd, const nana::rectangle& /*r_visual*/)
 			{
 				typedef category::flags cat_flags;
 
diff --git a/source/gui/element.cpp b/source/gui/element.cpp
index b2fdbb7f..e1f4b649 100644
--- a/source/gui/element.cpp
+++ b/source/gui/element.cpp
@@ -212,7 +212,7 @@ namespace nana
 		class menu_crook
 			: public crook_interface
 		{
-			bool draw(graph_reference graph, const ::nana::color&, const ::nana::color& fgcolor, const nana::rectangle& r, element_state es, const data& crook_data) override
+			bool draw(graph_reference graph, const ::nana::color&, const ::nana::color& fgcolor, const nana::rectangle& r, element_state, const data& crook_data) override
 			{
 				if(crook_data.check_state == state::unchecked)
 					return true;
@@ -266,7 +266,7 @@ namespace nana
 		class border_depressed
 			: public border_interface
 		{
-			bool draw(graph_reference graph, const ::nana::color& bgcolor, const ::nana::color& fgcolor, const ::nana::rectangle& r, element_state estate, unsigned weight)
+			bool draw(graph_reference graph, const ::nana::color& bgcolor, const ::nana::color&, const ::nana::rectangle& r, element_state estate, unsigned)
 			{
 				graph.rectangle(r, false, static_cast<color_rgb>((element_state::focus_hovered == estate || element_state::focus_normal == estate) ? 0x0595E2 : 0x999A9E));
 				graph.rectangle(::nana::rectangle(r).pare_off(1), false, bgcolor);
@@ -277,7 +277,7 @@ namespace nana
 		class arrow_solid_triangle
 			: public arrow_interface
 		{
-			bool draw(graph_reference graph, const ::nana::color& bgcolor, const ::nana::color& fgcolor, const ::nana::rectangle& r, element_state estate, direction dir) override
+			bool draw(graph_reference graph, const ::nana::color&, const ::nana::color&, const ::nana::rectangle& r, element_state, direction dir) override
 			{
 				::nana::point pos{ r.x + 3, r.y + 3 };
 				switch (dir)
@@ -318,7 +318,7 @@ namespace nana
 		class arrow_hollow_triangle
 			: public arrow_interface
 		{
-			bool draw(graph_reference graph, const ::nana::color& bgcolor, const ::nana::color& fgcolor, const ::nana::rectangle& r, element_state estate, ::nana::direction dir) override
+			bool draw(graph_reference graph, const ::nana::color&, const ::nana::color&, const ::nana::rectangle& r, element_state, ::nana::direction dir) override
 			{
 				int x = r.x + 3;
 				int y = r.y + 3;
@@ -364,7 +364,7 @@ namespace nana
 		class arrowhead
 			: public arrow_interface
 		{
-			bool draw(graph_reference graph, const ::nana::color& bgcolor, const ::nana::color& fgcolor, const ::nana::rectangle& r, element_state estate, ::nana::direction dir) override
+			bool draw(graph_reference graph, const ::nana::color&, const ::nana::color&, const ::nana::rectangle& r, element_state, ::nana::direction dir) override
 			{
 				int x = r.x;
 				int y = r.y + 5;
@@ -425,7 +425,7 @@ namespace nana
 		class arrow_double
 			: public arrow_interface
 		{
-			bool draw(graph_reference graph, const ::nana::color& bgcolor, const ::nana::color& fgcolor, const ::nana::rectangle& r, element_state estate, ::nana::direction dir) override
+			bool draw(graph_reference graph, const ::nana::color&, const ::nana::color&, const ::nana::rectangle& r, element_state, ::nana::direction dir) override
 			{
 				int x = r.x;
 				int y = r.y;
@@ -486,7 +486,7 @@ namespace nana
 		class annex_button
 			: public element_interface
 		{
-			bool draw(graph_reference graph, const ::nana::color& arg_bgcolor, const ::nana::color& fgcolor, const rectangle& r, element_state estate) override
+			bool draw(graph_reference graph, const ::nana::color& arg_bgcolor, const ::nana::color&, const rectangle& r, element_state estate) override
 			{
 				auto bgcolor = arg_bgcolor;
 
diff --git a/source/gui/msgbox.cpp b/source/gui/msgbox.cpp
index dd20cf6e..8d4914f6 100644
--- a/source/gui/msgbox.cpp
+++ b/source/gui/msgbox.cpp
@@ -702,7 +702,7 @@ namespace nana
 
 		impl->spinbox.value(std::to_string(impl->value));
 
-		impl->dock.events().resized.connect_unignorable([impl, label_px, value_px](const ::nana::arg_resized& arg)
+		impl->dock.events().resized.connect_unignorable([impl, label_px, value_px](const ::nana::arg_resized&)
 		{
 			impl->label.size({ label_px, 24 });
 			impl->spinbox.size({ value_px, 24 });
@@ -780,7 +780,7 @@ namespace nana
 
 		impl->spinbox.value(std::to_string(impl->value));
 
-		impl->dock.events().resized.connect_unignorable([impl, label_px, value_px](const ::nana::arg_resized& arg)
+		impl->dock.events().resized.connect_unignorable([impl, label_px, value_px](const ::nana::arg_resized&)
 		{
 			impl->label.size(::nana::size{ label_px, 24 });
 			impl->spinbox.size(::nana::size{ value_px, 24 });
diff --git a/source/gui/notifier.cpp b/source/gui/notifier.cpp
index 4e98e037..4a9f6ac3 100644
--- a/source/gui/notifier.cpp
+++ b/source/gui/notifier.cpp
@@ -314,6 +314,8 @@ namespace nana
 
 		::Shell_NotifyIcon(impl_->icon_added ? NIM_MODIFY : NIM_ADD, &icon_data);
 		impl_->icon_added = true;
+#else
+		static_cast<void>(str); //to eliminate unused parameter compiler warning.
 #endif
 	}
 
@@ -330,6 +332,8 @@ namespace nana
 			impl_->set_icon(impl_->icon_handle);
 			::DestroyIcon(pre_icon);
 		}
+#else
+		static_cast<void>(icon_file); //to eliminate unused parameter compiler warning
 #endif	
 	}
 
@@ -338,6 +342,8 @@ namespace nana
 #if defined(NANA_WINDOWS)
 		auto icon = (HICON)::LoadImage(0, to_wstring(icon_file).data(), IMAGE_ICON, 0, 0, LR_LOADFROMFILE);
 		impl_->icons.push_back(icon);
+#else
+		static_cast<void>(icon_file); //to eliminate unused parameter compiler warning.
 #endif
 	}
 
@@ -352,6 +358,8 @@ namespace nana
 		}
 		else
 			impl_->ani_timer.stop();
+#else
+		static_cast<void>(ms); //to eliminate unused parameter compiler warning.
 #endif
 	}
 
diff --git a/source/gui/place.cpp b/source/gui/place.cpp
index df89bbeb..1a0e5cb1 100644
--- a/source/gui/place.cpp
+++ b/source/gui/place.cpp
@@ -524,7 +524,7 @@ namespace nana
 		//It will delete the element and recollocate when the window destroyed.
 		event_handle _m_make_destroy(window wd)
 		{
-			return API::events(wd).destroy.connect([this, wd](const arg_destroy& arg)
+			return API::events(wd).destroy.connect([this, wd](const arg_destroy&)
 			{
 				for (auto i = elements.begin(), end = elements.end(); i != end; ++i)
 				{
@@ -1127,7 +1127,7 @@ namespace nana
 			}
 		}
 
-		void collocate(window wd) override
+		void collocate(window) override
 		{
 			if (!field || !(visible && display))
 				return;
@@ -1563,7 +1563,7 @@ namespace nana
 			}
 		}
 
-		void collocate(window wd) override
+		void collocate(window) override
 		{
 			if (!dockable_field)
 			{
diff --git a/source/gui/programming_interface.cpp b/source/gui/programming_interface.cpp
index 12670941..e36e1a36 100644
--- a/source/gui/programming_interface.cpp
+++ b/source/gui/programming_interface.cpp
@@ -104,8 +104,7 @@ namespace API
 			{
 				if (iwd->effect.edge_nimbus == effects::edge_nimbus::none)
 				{
-					basic_window::edge_nimbus_action ena = { iwd };
-					cont.push_back(ena);
+					cont.push_back(basic_window::edge_nimbus_action{ iwd, false});
 				}
 				iwd->effect.edge_nimbus = static_cast<effects::edge_nimbus>(static_cast<unsigned>(en) | static_cast<unsigned>(iwd->effect.edge_nimbus));
 			}
diff --git a/source/gui/screen.cpp b/source/gui/screen.cpp
index 1a0be98b..da390bda 100644
--- a/source/gui/screen.cpp
+++ b/source/gui/screen.cpp
@@ -167,6 +167,8 @@ namespace nana
 				}
 			}
 		}
+#else
+		static_cast<void>(pos); //to eliminate unused parameter compiler warning.
 #endif
 		return get_primary();
 	}
diff --git a/source/gui/tooltip.cpp b/source/gui/tooltip.cpp
index ac76b7d6..433c247b 100644
--- a/source/gui/tooltip.cpp
+++ b/source/gui/tooltip.cpp
@@ -227,7 +227,7 @@ namespace nana
 					window_->tooltip_move(API::cursor_position(), true);
 				}
 
-				void show_duration(window wd, point pos, const std::string& text, std::size_t duration)
+				void show_duration(window /*wd*/, point pos, const std::string& text, std::size_t duration)
 				{
 					if (nullptr == window_ || window_->tooltip_empty())
 					{
diff --git a/source/gui/widgets/button.cpp b/source/gui/widgets/button.cpp
index 301c07c7..f1541cfa 100644
--- a/source/gui/widgets/button.cpp
+++ b/source/gui/widgets/button.cpp
@@ -163,7 +163,7 @@ namespace nana{	namespace drawerbase
 			_m_press(graph, false);
 		}
 
-		void trigger::key_press(graph_reference graph, const arg_keyboard& arg)
+		void trigger::key_press(graph_reference, const arg_keyboard& arg)
 		{
 			bool ch_tabstop_next;
 			switch(arg.key)
diff --git a/source/gui/widgets/checkbox.cpp b/source/gui/widgets/checkbox.cpp
index 4a14a7fc..c535378c 100644
--- a/source/gui/widgets/checkbox.cpp
+++ b/source/gui/widgets/checkbox.cpp
@@ -216,7 +216,7 @@ namespace nana{ namespace drawerbase
 			uiobj.check(false);
 			uiobj.react(false);
 
-			element_tag el = {};
+			element_tag el;
 
 			el.uiobj = &uiobj;
 
diff --git a/source/gui/widgets/combox.cpp b/source/gui/widgets/combox.cpp
index c5df35f8..a4631668 100644
--- a/source/gui/widgets/combox.cpp
+++ b/source/gui/widgets/combox.cpp
@@ -615,7 +615,7 @@ namespace nana
 					}
 				}
 
-				void trigger::mouse_down(graph_reference graph, const arg_mouse& arg)
+				void trigger::mouse_down(graph_reference, const arg_mouse& arg)
 				{
 					//drawer_->set_mouse_press(true);
 					drawer_->set_button_state(element_state::pressed, false);
@@ -633,7 +633,7 @@ namespace nana
 					}
 				}
 
-				void trigger::mouse_up(graph_reference graph, const arg_mouse& arg)
+				void trigger::mouse_up(graph_reference, const arg_mouse& arg)
 				{
 					if (drawer_->widget_ptr()->enabled() && !drawer_->has_lister())
 					{
@@ -660,7 +660,7 @@ namespace nana
 					}
 				}
 
-				void trigger::mouse_wheel(graph_reference graph, const arg_wheel& arg)
+				void trigger::mouse_wheel(graph_reference, const arg_wheel& arg)
 				{
 					if(drawer_->widget_ptr()->enabled())
 					{
@@ -718,7 +718,7 @@ namespace nana
 					API::lazy_refresh();
 				}
 
-				void trigger::key_char(graph_reference graph, const arg_keyboard& arg)
+				void trigger::key_char(graph_reference, const arg_keyboard& arg)
 				{
 					if (drawer_->editor()->respond_char(arg))
 						API::lazy_refresh();
diff --git a/source/gui/widgets/form.cpp b/source/gui/widgets/form.cpp
index eab587ad..af43ea37 100644
--- a/source/gui/widgets/form.cpp
+++ b/source/gui/widgets/form.cpp
@@ -18,7 +18,7 @@ namespace nana
 		namespace form
 		{
 		//class trigger
-			void trigger::attached(widget_reference wdg, graph_reference graph)
+			void trigger::attached(widget_reference wdg, graph_reference)
 			{
 				wd_ = &wdg;
 				API::ignore_mouse_focus(wdg, true);
diff --git a/source/gui/widgets/label.cpp b/source/gui/widgets/label.cpp
index ed6c2828..d500eed9 100644
--- a/source/gui/widgets/label.cpp
+++ b/source/gui/widgets/label.cpp
@@ -437,7 +437,7 @@ namespace nana
 					return total_w;
 				}
 
-				bool _m_each_line(graph_reference graph, dstream::linecontainer& line, render_status& rs)
+				bool _m_each_line(graph_reference graph, dstream::linecontainer&, render_status& rs)
 				{
 					std::wstring text;
 					iterator block_start;
diff --git a/source/gui/widgets/listbox.cpp b/source/gui/widgets/listbox.cpp
index 3e214531..56eff953 100644
--- a/source/gui/widgets/listbox.cpp
+++ b/source/gui/widgets/listbox.cpp
@@ -2614,15 +2614,15 @@ namespace nana
 				return list_str ;
 			}
 
-            void es_lister::categ_selected(size_type cat, bool sel)
+			void es_lister::categ_selected(size_type cat, bool sel)
 			{
-                cat_proxy cpx{ess_,cat};
-                for (item_proxy &it : cpx )
-                {
-                    if (it.selected() != sel)
+				cat_proxy cpx{ess_,cat};
+				for (item_proxy &it : cpx )
+				{
+					if (it.selected() != sel)
 						it.select(sel);
-                }
-                last_selected_abs = last_selected_dpl = index_pair{cat, npos};
+				}
+				last_selected_abs = last_selected_dpl = index_pair{cat, npos};
 			}
 
 			class drawer_header_impl
@@ -3549,15 +3549,16 @@ namespace nana
 					}
 				}
 
-				void trigger::dbl_click(graph_reference graph, const arg_mouse& arg)
+				void trigger::dbl_click(graph_reference graph, const arg_mouse&)
 				{
 					if (essence_->pointer_where.first == essence_t::parts::header)
 						if (cursor::size_we == essence_->lister.wd_ptr()->cursor())
-                        {
- 			               if (essence(). auto_width(drawer_header_->item_spliter() )) // ? in order
-			                   essence().update();
-                           return;
-                       }
+						{
+							//adjust the width of column to its content.
+							if (essence_->auto_width(drawer_header_->item_spliter() ))
+								essence_->update();
+							return;
+						}
 
 					if (essence_->pointer_where.first != essence_t::parts::lister)
 						return;
@@ -3571,24 +3572,25 @@ namespace nana
 						if (!item_pos.is_category())	//being the npos of item.second is a category
 							return;
 
-                        arg_category ai(cat_proxy(essence_, item_pos.cat));
-                        lister.wd_ptr()->events().category_dbl_click.emit(ai);
+						arg_category ai(cat_proxy(essence_, item_pos.cat));
+						lister.wd_ptr()->events().category_dbl_click.emit(ai);
 
-                        if(!ai.category_change_blocked()){
-                            bool do_expand = (lister.expand(item_pos.cat) == false);
-                            lister.expand(item_pos.cat, do_expand);
+						if(!ai.category_change_blocked())
+						{
+							bool do_expand = (lister.expand(item_pos.cat) == false);
+							lister.expand(item_pos.cat, do_expand);
 
-                            if(false == do_expand)
-                            {
-                                auto last = lister.last();
-                                size_type n = essence_->number_of_lister_items(false);
-                                if (lister.backward(last, n, last))
-                                    offset_y = last;
-                            }
-                            essence_->adjust_scroll_life();
-                            refresh(graph);
-                            API::lazy_refresh();
-                        }
+							if(false == do_expand)
+							{
+								auto last = lister.last();
+								size_type n = essence_->number_of_lister_items(false);
+								if (lister.backward(last, n, last))
+									offset_y = last;
+							}
+							essence_->adjust_scroll_life();
+							refresh(graph);
+							API::lazy_refresh();
+						}
 					}
 				}
 
@@ -3603,8 +3605,8 @@ namespace nana
 				{
 					bool up = false;
 
-                    if (essence_->lister.size_categ()==1 && essence_->lister.size_item(0)==0)
-                       return ;
+					if (essence_->lister.size_categ()==1 && essence_->lister.size_item(0)==0)
+						return ;
 
 					switch(arg.key)
 					{
@@ -3622,49 +3624,46 @@ namespace nana
 						}
 						break;
 
-                    case keyboard::os_pageup :
+					case keyboard::os_pageup :
 						up = true;
-                    case keyboard::os_pagedown:
-                    {
-					    auto& scrl = essence_->scroll.v;
-                        if (! scrl.make_page_scroll(!up))
-                            return;
-                        essence_->lister.select_for_all(false);
+					case keyboard::os_pagedown:
+						{
+							auto& scrl = essence_->scroll.v;
+							if (! scrl.make_page_scroll(!up))
+								return;
+							essence_->lister.select_for_all(false);
 
-                        index_pair idx{essence_->scroll_y_dpl()};
-                        if (!up)
-                            essence_->lister.forward(idx, scrl.range()-1, idx);
+							index_pair idx{essence_->scroll_y_dpl()};
+							if (!up)
+								essence_->lister.forward(idx, scrl.range()-1, idx);
 
-                        if (idx.is_item())
-                           item_proxy::from_display(essence_, idx).select(true);
-                        else
-                            if(!essence_->lister.single_selection())
+							if (idx.is_item())
+								item_proxy::from_display(essence_, idx).select(true);
+							else if(!essence_->lister.single_selection())
 								essence_->lister.categ_selected(idx.cat, true);
 
-                        essence_->trace_last_selected_item ();
+							essence_->trace_last_selected_item ();
 
-                        break;
-                    }
-                    case keyboard::os_home:
-                    {
-                        essence_->lister.select_for_all(false);
+							break;
+						}
+					case keyboard::os_home:
+						{
+							essence_->lister.select_for_all(false);
 
-                        index_pair frst{essence_->lister.first()};
-                        if (frst.is_item())
-                           item_proxy::from_display(essence_, frst).select(true);
-                        else
-                            if(!essence_->lister.single_selection())
+							index_pair frst{essence_->lister.first()};
+							if (frst.is_item())
+								item_proxy::from_display(essence_, frst).select(true);
+							else if(!essence_->lister.single_selection())
 								essence_->lister.categ_selected(frst.cat, true);
 
-                        essence_->trace_last_selected_item ();
-                        break;
-                    }
-                    case keyboard::os_end:
-                        essence_->lister.select_for_all(false);
-                        item_proxy::from_display(essence_, essence_->lister.last()).select(true);
-                        essence_->trace_last_selected_item ();
-                       break;
-
+							essence_->trace_last_selected_item ();
+							break;
+						}
+					case keyboard::os_end:
+						essence_->lister.select_for_all(false);
+						item_proxy::from_display(essence_, essence_->lister.last()).select(true);
+						essence_->trace_last_selected_item ();
+						break;
 					default:
 						return;
 					}
@@ -3676,20 +3675,19 @@ namespace nana
 				{
 					switch(arg.key)
 					{
-                    case keyboard::copy:
-                    {
-                        export_options exp_opt {essence_->def_exp_options};
-                        exp_opt.columns_order = essence_->header.all_headers(true);
-                        exp_opt.only_selected_items = true;
-                        ::nana::system::dataexch().set(essence_->to_string(exp_opt));
-                        return;
-                    }
-                    case keyboard::select_all :
-                        essence_->lister.select_for_all(true);
+					case keyboard::copy:
+						{
+							export_options exp_opt {essence_->def_exp_options};
+							exp_opt.columns_order = essence_->header.all_headers(true);
+							exp_opt.only_selected_items = true;
+							::nana::system::dataexch().set(essence_->to_string(exp_opt));
+							return;
+						}
+					case keyboard::select_all :
+						essence_->lister.select_for_all(true);
 						refresh(graph);
-					    API::lazy_refresh();
-                        break;
-
+						API::lazy_refresh();
+						break;
 					default:
 						return;
 					}
@@ -3713,23 +3711,24 @@ namespace nana
 					}
 				}
 
-                /// the main porpose of this it to make obvious that item_proxy operate with absolute positions, and dont get moved during sort()
-                item_proxy item_proxy::from_display(essence_t *ess, const index_pair &relative)
-                {
-                    return item_proxy{ess, ess->lister.absolute_pair(relative)};
-                }
-                item_proxy item_proxy::from_display(const index_pair &relative) const
-                {
-                    return item_proxy{ess_, ess_->lister.absolute_pair(relative)};
-                }
+				/// the main porpose of this it to make obvious that item_proxy operate with absolute positions, and dont get moved during sort()
+				item_proxy item_proxy::from_display(essence_t *ess, const index_pair &relative)
+				{
+					return item_proxy{ess, ess->lister.absolute_pair(relative)};
+				}
 
-                /// posible use: last_selected_display = last_selected.to_display().item; use with caution, it get invalidated after a sort()
-                index_pair item_proxy::to_display() const
-                {
-                    return ess_->lister.relative_pair(pos_);
-                }
+				item_proxy item_proxy::from_display(const index_pair &relative) const
+				{
+					return item_proxy{ess_, ess_->lister.absolute_pair(relative)};
+				}
 
-                bool item_proxy::empty() const
+				/// posible use: last_selected_display = last_selected.to_display().item; use with caution, it get invalidated after a sort()
+				index_pair item_proxy::to_display() const
+				{
+					return ess_->lister.relative_pair(pos_);
+				}
+
+				bool item_proxy::empty() const
 				{
 					return !ess_;
 				}
@@ -3752,14 +3751,14 @@ namespace nana
 					return cat_->items.at(pos_.item).flags.checked;
 				}
 
-                /// is ignored if no change (maybe set last_selected anyway??), but if change emit event, deselect others if need ans set/unset last_selected
-                item_proxy & item_proxy::select(bool s)
+				/// is ignored if no change (maybe set last_selected anyway??), but if change emit event, deselect others if need ans set/unset last_selected
+				item_proxy & item_proxy::select(bool s)
 				{
 					auto & m = cat_->items.at(pos_.item);       // a ref to the real item     // what is pos is a cat?
 					if(m.flags.selected == s) return *this;     // ignore if no change
 					m.flags.selected = s;                       // actually change selection
 
-                    arg_listbox arg{*this, s};
+					arg_listbox arg{*this, s};
 					ess_->lister.wd_ptr()->events().selected.emit(arg);
 
 					if (m.flags.selected)
@@ -4394,7 +4393,7 @@ namespace nana
 		}
 		unsigned listbox::auto_width(size_type pos, unsigned max)
 		{
-            auto & ess = _m_ess();
+			auto & ess = _m_ess();
 			unsigned max_w = ess.auto_width(pos, max);
 			ess.update();
 			return max_w;
@@ -4480,34 +4479,33 @@ namespace nana
 			return *this;
 		}
 
-        listbox::item_proxy listbox::at(const index_pair& pos_abs) const
+		listbox::item_proxy listbox::at(const index_pair& pos_abs) const
 		{
 			return at(pos_abs.cat).at(pos_abs.item);
 		}
 
 
 		// Contributed by leobackes(pr#97)
-        listbox::index_pair listbox::at ( const point& pos ) const
-        {
-            auto & ess=_m_ess();
-            auto _where=ess.where(pos.x, pos.y);
-            index_pair item_pos{npos,npos};
-            if(_where.first==drawerbase::listbox::essence_t::parts::lister){
-                auto & offset_y = ess.scroll.offset_y_dpl;
-                ess.lister.forward(offset_y, _where.second, item_pos);
-            }
-            return item_pos;
-        }
+		listbox::index_pair listbox::at ( const point& pos ) const
+		{
+			auto & ess=_m_ess();
+			auto _where=ess.where(pos.x, pos.y);
+			index_pair item_pos{npos,npos};
+			if(_where.first==drawerbase::listbox::essence_t::parts::lister)
+			{
+				auto & offset_y = ess.scroll.offset_y_dpl;
+				ess.lister.forward(offset_y, _where.second, item_pos);
+			}
+			return item_pos;
+		}
 
 		//Contributed by leobackes(pr#97)
-        listbox::columns_indexs listbox::column_from_pos ( const point& pos )
-        {
-            auto & ess=_m_ess();
-            columns_indexs col=ess.header.item_by_x(pos.x - 2 - ess.scroll.offset_x);
-            return col;
-        }
-
-
+		listbox::columns_indexs listbox::column_from_pos ( const point& pos )
+		{
+			auto & ess=_m_ess();
+			columns_indexs col=ess.header.item_by_x(pos.x - 2 - ess.scroll.offset_x);
+			return col;
+		}
 
 		void listbox::insert(const index_pair& pos, std::string text)
 		{
diff --git a/source/gui/widgets/skeletons/text_editor.cpp b/source/gui/widgets/skeletons/text_editor.cpp
index fc6086cc..79731abf 100644
--- a/source/gui/widgets/skeletons/text_editor.cpp
+++ b/source/gui/widgets/skeletons/text_editor.cpp
@@ -53,7 +53,7 @@ namespace nana{	namespace widgets
 				return cmd_;
 			}
 
-			virtual bool merge(const undoable_command_interface<EnumCommand>& rhs) override
+			virtual bool merge(const undoable_command_interface<EnumCommand>&) override
 			{
 				return false;
 			}
@@ -273,8 +273,8 @@ namespace nana{	namespace widgets
 				: editor_(editor)
 			{}
 
-			void merge_lines(std::size_t first, std::size_t second) override{}
-			void add_lines(std::size_t pos, std::size_t lines) override{}
+			void merge_lines(std::size_t, std::size_t) override{}
+			void add_lines(std::size_t, std::size_t) override{}
 			void pre_calc_line(std::size_t, unsigned) override{}
 			void pre_calc_lines(unsigned) override{}
 
@@ -283,12 +283,12 @@ namespace nana{	namespace widgets
 				return editor_.textbase_.lines();
 			}
 
-			std::size_t take_lines(std::size_t pos) const override
+			std::size_t take_lines(std::size_t) const override
 			{
 				return 1;
 			}
 
-			void update_line(std::size_t textline, std::size_t secondary_before) override
+			void update_line(std::size_t textline, std::size_t) override
 			{
 				int top = editor_._m_text_top_base() + static_cast<int>(editor_.line_height() * (textline - editor_.points_.offset.y));
 				editor_.graph_.rectangle({ editor_.text_area_.area.x, top, editor_.text_area_.area.width, editor_.line_height() }, true, API::bgcolor(editor_.window_));
diff --git a/source/gui/widgets/spinbox.cpp b/source/gui/widgets/spinbox.cpp
index 880fa7f1..da0a8bd0 100644
--- a/source/gui/widgets/spinbox.cpp
+++ b/source/gui/widgets/spinbox.cpp
@@ -518,7 +518,7 @@ namespace nana
 				impl_->render();
 			}
 
-			void drawer::focus(graph_reference, const arg_focus& arg)
+			void drawer::focus(graph_reference, const arg_focus&)
 			{
 				impl_->reset_text();
 				impl_->render();
@@ -578,7 +578,7 @@ namespace nana
 				}
 			}
 
-			void drawer::resized(graph_reference graph, const arg_resized& arg)
+			void drawer::resized(graph_reference, const arg_resized&)
 			{
 				impl_->reset_text_area();
 				impl_->render();
diff --git a/source/gui/widgets/tabbar.cpp b/source/gui/widgets/tabbar.cpp
index 8aa7037e..9e1c05e0 100644
--- a/source/gui/widgets/tabbar.cpp
+++ b/source/gui/widgets/tabbar.cpp
@@ -43,7 +43,7 @@ namespace nana
 				: public item_renderer
 			{
 			private:
-				virtual void background(graph_reference graph, const nana::rectangle& r, const ::nana::color& bgcolor)
+				virtual void background(graph_reference graph, const nana::rectangle&, const ::nana::color& bgcolor)
 				{
 					if(bgcolor_ != bgcolor)
 					{
@@ -59,7 +59,6 @@ namespace nana
 
 				virtual void item(graph_reference graph, const item_t& m, bool active, state_t sta)
 				{
-					//*
 					const nana::rectangle & r = m.r;
 					color bgcolor;
 					color blcolor;
@@ -961,7 +960,8 @@ namespace nana
 					auto bgcolor = API::bgcolor(basis_.wd);
 					auto fgcolor = API::fgcolor(basis_.wd);
 
-					item_renderer::item_t m{ ::nana::rectangle{ basis_.graph->size() } };
+					item_renderer::item_t m;
+					m.r = ::nana::rectangle{ basis_.graph->size() };
 
 					basis_.renderer->background(*basis_.graph, m.r, bgcolor);
 
diff --git a/source/gui/widgets/textbox.cpp b/source/gui/widgets/textbox.cpp
index a4d4d499..8fedd8eb 100644
--- a/source/gui/widgets/textbox.cpp
+++ b/source/gui/widgets/textbox.cpp
@@ -88,7 +88,7 @@ namespace drawerbase {
 			editor_ = nullptr;
 		}
 
-		void drawer::refresh(graph_reference graph)
+		void drawer::refresh(graph_reference)
 		{
 			editor_->render(API::is_focus_ready(*widget_));
 		}
@@ -121,7 +121,7 @@ namespace drawerbase {
 				API::lazy_refresh();
 		}
 
-		void drawer::mouse_up(graph_reference graph, const arg_mouse& arg)
+		void drawer::mouse_up(graph_reference, const arg_mouse& arg)
 		{
 			if(editor_->mouse_pressed(arg))
 				API::lazy_refresh();
diff --git a/source/gui/wvl.cpp b/source/gui/wvl.cpp
index 1b475c80..6877ef41 100644
--- a/source/gui/wvl.cpp
+++ b/source/gui/wvl.cpp
@@ -82,8 +82,12 @@ namespace nana
 		if (t.joinable())
 			t.join();
 
-    #else
-			pump();
+	#else
+		static_cast<void>(wait);
+		static_cast<void>(wait_end);
+		static_cast<void>(f); //to eliminte unused parameter compiler warning.
+
+		pump();
 	#endif
 	}
 }//end namespace nana
diff --git a/source/paint/graphics.cpp b/source/paint/graphics.cpp
index 07153126..57d8138f 100644
--- a/source/paint/graphics.cpp
+++ b/source/paint/graphics.cpp
@@ -867,7 +867,7 @@ namespace paint
 				::DeleteObject(hBmp);
 				::DeleteDC(hdcMem);
 #elif defined(NANA_X11)
-
+				static_cast<void>(file_utf8);	//eliminate unused parameter compil warning.
 #endif
 			}
 		}
@@ -1201,6 +1201,10 @@ namespace paint
 					if(solid)
 						rectangle(::nana::rectangle(r).pare_off(1), true, solid_clr);
 				}
+
+				//eliminate unused parameter compiler warning.
+				static_cast<void>(radius_x);
+				static_cast<void>(radius_y);
 #endif
 			}
 		}
diff --git a/source/paint/image.cpp b/source/paint/image.cpp
index f14de479..3d23e3f5 100644
--- a/source/paint/image.cpp
+++ b/source/paint/image.cpp
@@ -73,7 +73,8 @@ namespace paint
 					return true;
 				}
 #else
-				if(is_ico_){}	//kill the unused compiler warning in Linux.
+				static_cast<void>(is_ico_);	 //eliminate the unused compiler warning in Linux.
+				static_cast<void>(file);   //to eliminate the unused parameter compiler warning.
 #endif
 				return false;
 			}
@@ -98,7 +99,9 @@ namespace paint
 					}
 				}
 #else
-				if(is_ico_){}	//kill the unused compiler warning in Linux.
+				static_cast<void>(is_ico_);	//kill the unused compiler warning in Linux.
+				static_cast<void>(data);	//to eliminate unused parameter compiler warning.
+				static_cast<void>(bytes);
 #endif
 				return false;
 			}
@@ -129,6 +132,9 @@ namespace paint
 				{
 #if defined(NANA_WINDOWS)
 					::DrawIconEx(graph.handle()->context, p_dst.x, p_dst.y, *ptr_, src_r.width, src_r.height, 0, 0, DI_NORMAL);
+#else
+					static_cast<void>(src_r);	//eliminate unused parameter compiler warning.
+					static_cast<void>(p_dst);
 #endif
 				}
 			}
@@ -139,6 +145,8 @@ namespace paint
 				{
 #if defined(NANA_WINDOWS)
 					::DrawIconEx(graph.handle()->context, r.x, r.y, *ptr_, r.width, r.height, 0, 0, DI_NORMAL);
+#else
+					static_cast<void>(r); //eliminate unused parameter compiler warning.
 #endif
 				}
 			}
diff --git a/source/paint/pixel_buffer.cpp b/source/paint/pixel_buffer.cpp
index c3330c8d..574c8951 100644
--- a/source/paint/pixel_buffer.cpp
+++ b/source/paint/pixel_buffer.cpp
@@ -977,7 +977,7 @@ namespace nana{	namespace paint
 		}
 	}
 
-	void pixel_buffer::gradual_rectangle(const ::nana::rectangle& draw_rct, const ::nana::color& from, const ::nana::color& to, double fade_rate, bool vertical)
+	void pixel_buffer::gradual_rectangle(const ::nana::rectangle& draw_rct, const ::nana::color& from, const ::nana::color& to, double /*fade_rate*/, bool vertical)
 	{
 		auto sp = storage_.get();
 		if (nullptr == sp) return;
diff --git a/source/system/dataexch.cpp b/source/system/dataexch.cpp
index 992a76d3..d229dea0 100644
--- a/source/system/dataexch.cpp
+++ b/source/system/dataexch.cpp
@@ -82,31 +82,35 @@ namespace nana{ namespace system{
 			// Bitmaps are huge, so to avoid unnegligible extra copy, this routine does not use private _m_set method.
 			HGLOBAL h_gmem = ::GlobalAlloc(GHND | GMEM_SHARE, header_size + bitmap_bytes);
 			void * gmem = ::GlobalLock(h_gmem);
-			if (gmem) {
-                char* p = (char*)gmem;
-                // Fix BITMAPINFOHEADER obtained from GetDIBits WinAPI
-                bmi.bmiHeader.biCompression = BI_RGB;
-                bmi.bmiHeader.biHeight = ::abs(bmi.bmiHeader.biHeight);
-                memcpy(p, &bmi, header_size);
-                p += header_size;
-                // many programs do not support bottom-up DIB, so reversing row order is needed.
-                for (int y=0; y<bmi.bmiHeader.biHeight; ++y) {
-                    memcpy(p, pbuffer.raw_ptr(bmi.bmiHeader.biHeight - 1 - y), bytes_per_line);
-                    p += bytes_per_line;
-                }
-                if (::GlobalUnlock(h_gmem) || GetLastError() == NO_ERROR)
-                    if (::OpenClipboard(::GetFocus()))
-                        if (::EmptyClipboard())
-                            if (::SetClipboardData(CF_DIB, h_gmem))
-                                if (::CloseClipboard())
-                                    return true;
+			if (gmem)
+			{
+				char* p = (char*)gmem;
+				// Fix BITMAPINFOHEADER obtained from GetDIBits WinAPI
+				bmi.bmiHeader.biCompression = BI_RGB;
+				bmi.bmiHeader.biHeight = ::abs(bmi.bmiHeader.biHeight);
+				std::memcpy(p, &bmi, header_size);
+				p += header_size;
+				// many programs do not support bottom-up DIB, so reversing row order is needed.
+				for (int y=0; y<bmi.bmiHeader.biHeight; ++y)
+				{
+					memcpy(p, pbuffer.raw_ptr(bmi.bmiHeader.biHeight - 1 - y), bytes_per_line);
+					p += bytes_per_line;
+				}
+
+				if (::GlobalUnlock(h_gmem) || GetLastError() == NO_ERROR)
+					if (::OpenClipboard(::GetFocus()))
+						if (::EmptyClipboard())
+							if (::SetClipboardData(CF_DIB, h_gmem))
+								if (::CloseClipboard())
+									return true;
 			}
-		    assert(false);
+			assert(false);
 			::GlobalFree(h_gmem);
 			return false;
 
 //#elif defined(NANA_X11)
 #else
+			static_cast<void>(g); //eliminate unused parameter compiler warning.
 			throw "not implemented yet.";
 			return false;
 #endif
diff --git a/source/system/platform.cpp b/source/system/platform.cpp
index 042c5892..092c53e5 100644
--- a/source/system/platform.cpp
+++ b/source/system/platform.cpp
@@ -93,6 +93,7 @@ namespace system
 
 		return (::GetAsyncKeyState(button) != 0);
 #elif defined(NANA_LINUX) || defined(NANA_MACOS)
+		static_cast<void>(button);	//eliminate unused parameter compiler warning.
 		return false;
 #endif
 	}
diff --git a/source/system/shared_wrapper.cpp b/source/system/shared_wrapper.cpp
index dce6d621..124f2822 100644
--- a/source/system/shared_wrapper.cpp
+++ b/source/system/shared_wrapper.cpp
@@ -54,7 +54,7 @@ namespace system
 				::FreeLibrary(reinterpret_cast<HMODULE>(handle));
 #endif
 			}
-		}; //end struct shared_helper
+		} //end namespace shared_helper
 	}//end namespace detail
 
 
diff --git a/source/unicode_bidi.cpp b/source/unicode_bidi.cpp
index 5ef940ec..f92bd5ee 100644
--- a/source/unicode_bidi.cpp
+++ b/source/unicode_bidi.cpp
@@ -584,7 +584,7 @@ namespace nana
 			_m_resolve_weak_types();
 			_m_resolve_neutral_types();
 			_m_resolve_implicit_levels();
-			_m_reordering_resolved_levels(str, reordered);
+			_m_reordering_resolved_levels(reordered);
 		}
 
 		unsigned unicode_bidi::_m_paragraph_level(const char_type * begin, const char_type * end)
@@ -885,7 +885,7 @@ namespace nana
 			}
 		}
 
-		void unicode_bidi::_m_reordering_resolved_levels(const char_type * str, std::vector<entity> & reordered)
+		void unicode_bidi::_m_reordering_resolved_levels(std::vector<entity> & reordered)
 		{
 			reordered = levels_;