feat: serde::redacted convenience serialize_with - serialize with…

…out exposing

# Todo
- [ ] Document function with rustdoc
- [ ] Update serde section in `README.md`

src/lib.rs

@@ -9,7 +9,7 @@ mod error;
 mod fake;
 mod ops;
 #[cfg(feature = "serde")]
-mod serde;
+pub mod serde;
 
 #[cfg(feature = "serde")]
 pub use crate::serde::expose_secret;

src/serde.rs

@@ -60,6 +60,12 @@ pub fn expose_secret<S: Serializer, T: Serialize>(
         .serialize(serializer)
 }
 
+#[cfg(feature = "serde")]
+#[inline]
+pub fn redacted<S: Serializer, T>(secret: &Secret<T>, serializer: S) -> Result<S::Ok, S::Error> {
+    format!("{secret:?}").serialize(serializer)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;