identity-service-api: Return a BTreeSet for get_supported_versions::Response::known_versions()

crates/ruma-identity-service-api/CHANGELOG.md

@@ -1,5 +1,23 @@
 # [unreleased]
 
+=======
+Breaking changes:
+
+- `get_supported_versions::Response::known_versions()` returns a
+  `BTreeSet<MatrixVersion>` instead of a `DoubleEndedIterator`.
+
+# 0.11.0
+
+Improvements:
+
+- The `unstable-exhaustive-types` cargo feature was replaced by the
+  `ruma_unstable_exhaustive_types` compile-time `cfg` setting. Like all `cfg`
+  settings, it can be enabled at compile-time with the `RUSTFLAGS` environment
+  variable, or inside `.cargo/config.toml`. It can also be enabled by setting
+  the `RUMA_UNSTABLE_EXHAUSTIVE_TYPES` environment variable.
+
+# 0.10.0
+
 Breaking changes:
 
 - Change type of `client_secret` field in `ThreePidOwnershipProof`

crates/ruma-identity-service-api/src/discovery/get_supported_versions.rs

@@ -10,7 +10,7 @@
 //!
 //! [spec]: https://spec.matrix.org/latest/identity-service-api/#get_matrixidentityversions
 
-use std::collections::BTreeMap;
+use std::collections::BTreeSet;
 
 use ruma_common::{
     api::{request, response, MatrixVersion, Metadata},
@@ -58,17 +58,12 @@ impl Response {
     /// The versions returned will be sorted from oldest to latest. Use [`.find()`][Iterator::find]
     /// or [`.rfind()`][DoubleEndedIterator::rfind] to look for a minimum or maximum version to use
     /// given some constraint.
-    pub fn known_versions(&self) -> impl DoubleEndedIterator<Item = MatrixVersion> {
+    pub fn known_versions(&self) -> BTreeSet<MatrixVersion> {
         self.versions
             .iter()
             // Parse, discard unknown versions
             .flat_map(|s| s.parse::<MatrixVersion>())
-            // Map to key-value pairs where the key is the major-minor representation
-            // (which can be used as a BTreeMap unlike MatrixVersion itself)
-            .map(|v| (v.into_parts(), v))
-            // Collect to BTreeMap
-            .collect::<BTreeMap<_, _>>()
-            // Return an iterator over just the values (`MatrixVersion`s)
-            .into_values()
+            // Collect to BTreeSet
+            .collect()
     }
 }