Registration fixes and improvements.

src/utils/string_key.rs

@@ -1,5 +1,5 @@
 use std::borrow::Borrow;
-use std::ffi::CString;
+use std::ffi::CStr;
 use std::fmt::{Display, Formatter};
 use std::hash::{Hash, Hasher};
 use std::ops::Deref;
@@ -106,18 +106,11 @@ impl Display for StringKey {
     }
 }
 
-impl Into<StringKey> for CString {
+impl Into<StringKey> for &CStr {
     fn into(self) -> StringKey {
         StringKey::new(self.to_str().unwrap())
     }
 }
-
-impl Into<StringKey> for &CString {
-    fn into(self) -> StringKey {
-        StringKey::new(self.to_str().unwrap())
-    }
-}
-
 /// Converts a character to lowercased in a const safe way.
 const fn to_lower(c: u8) -> u8 {
     if c >= b'A' && c <= b'Z' {