fix(coreaudio): prefer stereo output configuration on iOS

Author: roderickvd

CHANGELOG.md

@@ -119,6 +119,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **CoreAudio**: Streams no longer start automatically on creation; call `play()` manually.
 - **CoreAudio (iOS)**: `default_input_config()` and `default_output_config()` now prefer 48 kHz,
   then 44.1 kHz, then the maximum supported sample rate, instead of always taking the maximum.
+- **CoreAudio (iOS)**: `default_output_config()` now prefers stereo over the maximum channel count.
 - **JACK**: Timestamps now use the precise hardware deadline.
 - **JACK**: Buffer size change no longer invokes the error callback; internal buffers are resized
   without error.

src/host/coreaudio/ios/mod.rs

@@ -118,13 +118,14 @@ impl Device {
     }
 
     fn default_output_config(&self) -> Result<SupportedStreamConfig, Error> {
-        // Get the maximum channel count config from supported configs
-        let range = get_supported_stream_configs(false).last().ok_or_else(|| {
-            Error::with_message(
-                ErrorKind::UnsupportedConfig,
-                "No supported output configuration",
-            )
-        })?;
+        let range = get_supported_stream_configs(false)
+            .max_by(|a, b| a.cmp_default_heuristics(b))
+            .ok_or_else(|| {
+                Error::with_message(
+                    ErrorKind::UnsupportedConfig,
+                    "No supported output configuration",
+                )
+            })?;
         Ok(range
             .try_with_standard_sample_rate()
             .unwrap_or_else(|| range.with_max_sample_rate()))