Implement Key and Value for String

src/types.rs

@@ -489,6 +489,46 @@ impl Key for &str {
     }
 }
 
+impl Value for String {
+    type SelfType<'a> = String
+    where
+        Self: 'a;
+    type AsBytes<'a> = &'a str
+    where
+        Self: 'a;
+
+    fn fixed_width() -> Option<usize> {
+        None
+    }
+
+    fn from_bytes<'a>(data: &'a [u8]) -> String
+    where
+        Self: 'a,
+    {
+        std::str::from_utf8(data).unwrap().to_string()
+    }
+
+    fn as_bytes<'a, 'b: 'a>(value: &'a Self::SelfType<'b>) -> &'a str
+    where
+        Self: 'a,
+        Self: 'b,
+    {
+        value.as_str()
+    }
+
+    fn type_name() -> TypeName {
+        TypeName::internal("String")
+    }
+}
+
+impl Key for String {
+    fn compare(data1: &[u8], data2: &[u8]) -> Ordering {
+        let str1 = std::str::from_utf8(data1).unwrap();
+        let str2 = std::str::from_utf8(data2).unwrap();
+        str1.cmp(str2)
+    }
+}
+
 impl Value for char {
     type SelfType<'a> = char;
     type AsBytes<'a> = [u8; 3] where Self: 'a;

tests/basic_tests.rs

@@ -1150,6 +1150,38 @@ fn str_type() {
     assert!(iter.next().is_none());
 }
 
+#[test]
+fn string_type() {
+    let tmpfile = create_tempfile();
+    let db = Database::create(tmpfile.path()).unwrap();
+
+    let definition: TableDefinition<String, String> = TableDefinition::new("x");
+
+    let write_txn = db.begin_write().unwrap();
+    {
+        let mut table = write_txn.open_table(definition).unwrap();
+        table
+            .insert("hello".to_string(), "world".to_string())
+            .unwrap();
+    }
+    write_txn.commit().unwrap();
+
+    let read_txn = db.begin_read().unwrap();
+    let table = read_txn.open_table(definition).unwrap();
+    assert_eq!(
+        "world",
+        table.get("hello".to_string()).unwrap().unwrap().value()
+    );
+
+    let mut iter = table.iter().unwrap();
+    assert_eq!(iter.next().unwrap().unwrap().1.value(), "world");
+    assert!(iter.next().is_none());
+
+    let mut iter: Range<String, String> = table.range("a".to_string().."z".to_string()).unwrap();
+    assert_eq!(iter.next().unwrap().unwrap().1.value(), "world");
+    assert!(iter.next().is_none());
+}
+
 #[test]
 fn empty_type() {
     let tmpfile = create_tempfile();