add namespace

include/drive.h

@@ -4,6 +4,8 @@
 #include <vector>
 #include <memory>
 
+namespace drive {
+
 enum drive_type {
     dt_alipan,
     dt_filebrowser,
@@ -35,3 +37,5 @@ drive::ref new_drive(drive_type type);
 
 std::string hex_encode(const unsigned char* data, size_t len);
 std::string device_name();
+
+}