implement Display trait for Error

src/profile/bookmark/memory/error.rs

@@ -1,16 +1,18 @@
+use std::fmt::{Display, Formatter, Result};
+
 #[derive(Debug)]
 pub enum Error {
     Overwrite(String),
     Unexpected,
 }
 
-impl Error {
-    pub fn to_string(&self) -> String {
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter) -> Result {
         match self {
             Self::Overwrite(key) => {
-                format!("Overwrite attempt for existing record `{key}`")
+                write!(f, "Overwrite attempt for existing record `{key}`")
             }
-            Self::Unexpected => "Unexpected error".to_string(),
+            Self::Unexpected => write!(f, "Unexpected error"),
         }
     }
 }