Merge pull request #2197 from CosmWasm/co/iterator-default-impl

Add default impl for `Storage::range`

Author: chipshort

CHANGELOG.md

@@ -12,8 +12,11 @@ and this project adheres to
 
 - cosmwasm-std: Make fields of `IbcAckCallbackMsg` and `IbcTimeoutCallbackMsg`
   public. ([#2191])
+- cosmwasm-std: Add default implementation for `Storage::range` to make
+  `iterator` feature additive. ([#2197])
 
 [#2191]: https://github.com/CosmWasm/cosmwasm/pull/2191
+[#2197]: https://github.com/CosmWasm/cosmwasm/pull/2197
 
 ## [2.1.0] - 2024-07-11
 

packages/std/src/traits.rs

@@ -61,12 +61,17 @@ pub trait Storage {
     /// The bound `start` is inclusive and `end` is exclusive.
     /// If `start` is lexicographically greater than or equal to `end`, an empty range is described, mo matter of the order.
     #[cfg(feature = "iterator")]
+    #[allow(unused_variables)]
     fn range<'a>(
         &'a self,
         start: Option<&[u8]>,
         end: Option<&[u8]>,
         order: Order,
-    ) -> Box<dyn Iterator<Item = Record> + 'a>;
+    ) -> Box<dyn Iterator<Item = Record> + 'a> {
+        // This default implementation is just to avoid breaking code when enabling the `iterator` feature.
+        // Any actual `Storage` impl should override this method.
+        unimplemented!("This storage does not support ranging. Make sure to override the `range` method in your `Storage` implementation.")
+    }
 
     /// Allows iteration over a set of keys, either forwards or backwards.
     ///