fix some compiler warnings and errors for GCC

source/gui/notifier.cpp

@@ -331,6 +331,8 @@ namespace nana
 			impl_->set_icon(image_ico);
 			impl_->icon = image_ico;
 		}
+#else
+		static_cast<void>(icon_file);	//eliminate unused parameter warning
 #endif
 	}
 
@@ -341,6 +343,8 @@ namespace nana
 		auto icon_handle = paint::image_accessor::icon(image_ico);
 		if (icon_handle)
 			impl_->icons.emplace_back(static_cast<paint::image&&>(image_ico));
+#else
+		static_cast<void>(icon_file);	//eliminate unused parameter warning
 #endif
 	}
 

source/gui/place.cpp

@@ -472,8 +472,6 @@ namespace nana
 		if (depth < 0 || start_pos >= div.length())
 			return{};
 
-		const char* p = div.c_str() + start_pos;
-
 		while (depth >= 0)
 		{
 			auto pos = div.find_last_of("<>", start_pos);