add AsRef impls for PyBackedStr and PyBackedBytes (#3991)

* add `AsRef` impls for `PyBackedStr` and `PyBackedBytes`

* add newsfragment

Author: Icxolu

newsfragments/3991.added.md

@@ -0,0 +1 @@
+implemented `AsRef<str>` and `AsRef<[u8]>` for `PyBackedStr`, `AsRef<[u8]>` for `PyBackedBytes`.

src/pybacked.rs

@@ -27,6 +27,18 @@ impl Deref for PyBackedStr {
     }
 }
 
+impl AsRef<str> for PyBackedStr {
+    fn as_ref(&self) -> &str {
+        self
+    }
+}
+
+impl AsRef<[u8]> for PyBackedStr {
+    fn as_ref(&self) -> &[u8] {
+        self.as_bytes()
+    }
+}
+
 impl TryFrom<Bound<'_, PyString>> for PyBackedStr {
     type Error = PyErr;
     fn try_from(py_string: Bound<'_, PyString>) -> Result<Self, Self::Error> {
@@ -82,6 +94,12 @@ impl Deref for PyBackedBytes {
     }
 }
 
+impl AsRef<[u8]> for PyBackedBytes {
+    fn as_ref(&self) -> &[u8] {
+        self
+    }
+}
+
 impl From<Bound<'_, PyBytes>> for PyBackedBytes {
     fn from(py_bytes: Bound<'_, PyBytes>) -> Self {
         let b = py_bytes.as_bytes();