From 4eb0344f01291045069b45b229f36da5d87a33e1 Mon Sep 17 00:00:00 2001
From: teor <teor@riseup.net>
Date: Sat, 7 Aug 2021 02:39:32 +1000
Subject: [PATCH] impl TryFrom for vector references for AtLeastOne (#2578)

Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
---
 zebra-chain/src/serialization/constraint.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/zebra-chain/src/serialization/constraint.rs b/zebra-chain/src/serialization/constraint.rs
index ecbfb8da..1aac711c 100644
--- a/zebra-chain/src/serialization/constraint.rs
+++ b/zebra-chain/src/serialization/constraint.rs
@@ -91,6 +91,23 @@ impl<T> TryFrom<Vec<T>> for AtLeastOne<T> {
     }
 }
 
+impl<T> TryFrom<&Vec<T>> for AtLeastOne<T>
+where
+    T: Clone,
+{
+    type Error = SerializationError;
+
+    fn try_from(vec: &Vec<T>) -> Result<Self, Self::Error> {
+        if vec.is_empty() {
+            Err(SerializationError::Parse("expected at least one item"))
+        } else {
+            Ok(AtLeastOne {
+                inner: vec.to_vec(),
+            })
+        }
+    }
+}
+
 impl<T> TryFrom<&[T]> for AtLeastOne<T>
 where
     T: Clone,