RetryPolicy: Doc comments for RetryDecision

Author: Lorak-mmk

scylla/src/policies/retry/retry_policy.rs

@@ -17,11 +17,17 @@ pub struct RequestInfo<'a> {
     pub consistency: Consistency,
 }
 
+/// Returned by implementations of RetryPolicy. Instructs the driver on what
+/// to do about the request after it failed.
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum RetryDecision {
+    /// Request will be sent to the same shard on the same host.
     RetrySameTarget(Option<Consistency>), // None means that the same consistency should be used as before
+    /// Request will be sent to the next target generated by load balancing policy.
     RetryNextTarget(Option<Consistency>), // ditto
+    /// Fails the whole request.
     DontRetry,
+    /// Will cause the driver to return an empty successful response.
     IgnoreWriteError,
 }