diff --git a/twml/libtwml/include/twml/utilities.h b/twml/libtwml/include/twml/utilities.h
index a30b44aff..960d6625d 100644
--- a/twml/libtwml/include/twml/utilities.h
+++ b/twml/libtwml/include/twml/utilities.h
@@ -1,18 +1,21 @@
 #pragma once
-#ifdef __cplusplus
+
+#include <cstdint>
+#include <cstring>
+
 namespace twml {
 
-inline int64_t mixDiscreteIdAndValue(int64_t key, int64_t value) {
-  key ^= ((17LL + value) * 2654435761LL);
-  return key;
-}
+    inline int64_t mixDiscreteIdAndValue(int64_t key, int64_t value) {
+        key ^= ((17LL + value) * 2654435761LL);
+        return key;
+    }
 
-inline int64_t mixStringIdAndValue(int64_t key, int32_t str_len, const uint8_t *str) {
-  int32_t hash = 0;
-  for (int32_t i = 0; i < str_len; i++) {
-    hash = (31 * hash) + (int32_t)str[i];
-  }
-  return key ^ hash;
-}
-}
-#endif
\ No newline at end of file
+    inline int64_t mixStringIdAndValue(int64_t key, int32_t str_len, const uint8_t* str) {
+        const uint8_t* end = str + str_len;
+        while (str != end) {
+            key = (key * 31) + *str++;
+        }
+        return key;
+    }
+
+} // namespace twml