diff --git a/src/klotski_core/raw_code/convert.cc b/src/klotski_core/raw_code/convert.cc
index d99a452..a0434e2 100644
--- a/src/klotski_core/raw_code/convert.cc
+++ b/src/klotski_core/raw_code/convert.cc
@@ -1,4 +1,3 @@
-#include <stdexcept>
 #include "common.h"
 #include "raw_code.h"
 
@@ -12,20 +11,32 @@ CommonCode RawCode::to_common_code() const {
 }
 
 /// CommonCode to RawCode
-RawCode RawCode::from_common_code(const CommonCode &common_code) {
-    return RawCode(common_code); // load from common code
+RawCode::RawCode(CommonCode &&common_code) {
+    code = RawCode::extract(common_code.unwrap());
+}
+
+RawCode::RawCode(const CommonCode &common_code) {
+    code = RawCode::extract(common_code.unwrap());
 }
 
 RawCode RawCode::from_common_code(uint64_t common_code) {
-    return RawCode(CommonCode(common_code)); // load from common code
+    return RawCode(CommonCode(common_code));
 }
 
-RawCode RawCode::from_common_code(const std::string &common_code) {
-    return RawCode(CommonCode(common_code)); // load from common code
+RawCode RawCode::from_common_code(CommonCode &&common_code) {
+    return RawCode(std::forward<CommonCode>(common_code));
 }
 
-RawCode::RawCode(const CommonCode &common_code) {
-    code = RawCode::extract(common_code.unwrap()); // load from common code
+RawCode RawCode::from_common_code(std::string &&common_code) {
+    return RawCode(std::forward<CommonCode>(CommonCode(common_code)));
+}
+
+RawCode RawCode::from_common_code(const CommonCode &common_code) {
+    return RawCode(common_code);
+}
+
+RawCode RawCode::from_common_code(const std::string &common_code) {
+    return RawCode(CommonCode(common_code));
 }
 
 /// NOTE: ensure that input raw code is valid!
diff --git a/src/klotski_core/raw_code/raw_code.cc b/src/klotski_core/raw_code/raw_code.cc
index aec594d..65e2247 100644
--- a/src/klotski_core/raw_code/raw_code.cc
+++ b/src/klotski_core/raw_code/raw_code.cc
@@ -1,6 +1,8 @@
 #include "common.h"
 #include "raw_code.h"
 
+using klotski::RawCode;
+
 namespace std {
     template<>
     struct hash<klotski::RawCode> {
@@ -18,6 +20,10 @@ namespace std {
 }
 
 namespace klotski {
+    bool RawCode::operator==(uint64_t raw_code) const {
+        return this->code == raw_code;
+    }
+
     bool RawCode::operator==(const RawCode &raw_code) const {
         return this->code == raw_code.code;
     }
@@ -61,7 +67,7 @@ namespace klotski {
     }
 }
 
-bool klotski::RawCode::check(uint64_t raw_code) { // check whether raw code is valid
+bool RawCode::check(uint64_t raw_code) { // check whether raw code is valid
     ///     MASK_1x2          MASK_2x1         MASK_2x2
     ///  000 100 000 000   000 000 000 000  000 100 000 000
     ///  000 000 000 000   100 000 000 000  100 100 000 000
diff --git a/src/klotski_core/raw_code/raw_code.h b/src/klotski_core/raw_code/raw_code.h
index 0bb5d54..1e0b1a5 100644
--- a/src/klotski_core/raw_code/raw_code.h
+++ b/src/klotski_core/raw_code/raw_code.h
@@ -54,11 +54,19 @@ namespace klotski {
     };
 
     class RawCode {
+        uint64_t code;
+        RawCode() = default; // unsafe initialize
+
+        static uint64_t compact(uint64_t raw_code); // raw code -> common code
+        static uint64_t extract(uint64_t common_code); // common code -> raw code
+
     public:
+        /// RawCode validity check
         bool valid() const;
         static bool check(uint64_t raw_code);
 
         /// Operators of RawCode
+        bool operator==(uint64_t raw_code) const;
         bool operator==(const RawCode &raw_code) const;
         constexpr explicit operator uint64_t() const { return code; }
         friend std::ostream& operator<<(std::ostream &out, const RawCode &self);
@@ -69,23 +77,34 @@ namespace klotski {
 
         /// RawCode constructors
         explicit RawCode(uint64_t raw_code);
+        explicit RawCode(CommonCode &&common_code);
         explicit RawCode(const CommonCode &common_code);
 
-        /// Rust-style initialization
+        /// Static initialization
         static RawCode create(uint64_t raw_code);
         static RawCode unsafe_create(uint64_t raw_code);
 
         static RawCode from_common_code(uint64_t common_code);
+        static RawCode from_common_code(CommonCode &&common_code);
+        static RawCode from_common_code(std::string &&common_code);
         static RawCode from_common_code(const CommonCode &common_code);
         static RawCode from_common_code(const std::string &common_code);
 
-        // TODO: mirror functions
-
-    private:
-        uint64_t code;
-        RawCode() = default; // unsafe initialize
-
-        static uint64_t compact(uint64_t raw_code);
-        static uint64_t extract(uint64_t common_code);
+        /// Mirror functions
+//        bool is_vertical_mirror() const;
+//        bool is_horizontal_mirror() const;
+//
+//        RawCode to_vertical_mirror() const;
+//        RawCode to_horizontal_mirror() const;
+//
+//        static bool is_vertical_mirror(RawCode &&raw_code);
+//        static bool is_horizontal_mirror(RawCode &&raw_code);
+//        static bool is_vertical_mirror(const RawCode &raw_code);
+//        static bool is_horizontal_mirror(const RawCode &raw_code);
+//
+//        static RawCode to_vertical_mirror(RawCode &&raw_code);
+//        static RawCode to_horizontal_mirror(RawCode &&raw_code);
+//        static RawCode to_vertical_mirror(const RawCode &raw_code);
+//        static RawCode to_horizontal_mirror(const RawCode &raw_code);
     };
 }