refactor: replace a From<Vec<Foo>> by FromIterator<Foo>

This is more versatile, makes the construction more visible, and can be used with collect.

faucet/src/faucet/mod.rs

@@ -33,10 +33,10 @@ pub trait Faucet {
     ) -> Result<FaucetReceipt, FaucetError>;
 }
 
-impl From<Vec<Object>> for FaucetReceipt {
-    fn from(v: Vec<Object>) -> Self {
-        Self {
-            sent: v.iter().map(|c| c.into()).collect(),
+impl<'a> FromIterator<&'a Object> for FaucetReceipt {
+    fn from_iter<T: IntoIterator<Item = &'a Object>>(iter: T) -> Self {
+        FaucetReceipt {
+            sent: iter.into_iter().map(|o| o.into()).collect(),
         }
     }
 }

faucet/src/faucet/simple_faucet.rs

@@ -174,6 +174,6 @@ impl Faucet for SimpleFaucet {
         let coins = self.get_coins(amounts).await?;
         let coin_ids = coins.iter().map(|c| c.id()).collect::<Vec<ObjectID>>();
         self.transfer_coins(&coin_ids, recipient).await?;
-        Ok(coins.into())
+        Ok(coins.iter().by_ref().collect())
     }
 }