add get_ref to SampleRateConverter

CHANGELOG.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - `DitherAlgorithm` enum for algorithm selection
   - `Source::dither()` function for applying dithering
 - Added `64bit` feature to opt-in to 64-bit sample precision (`f64`).
+- Added `SampleRateConverter::inner` to get underlying iterator by ref.
 
 ### Fixed
 - docs.rs will now document all features, including those that are optional.

src/conversions/sample_rate.rs

@@ -95,12 +95,18 @@ where
         self.input
     }
 
-    /// get mutable access to the iterator
+    /// Get mutable access to the iterator
     #[inline]
     pub fn inner_mut(&mut self) -> &mut I {
         &mut self.input
     }
 
+    /// Get a reference to the underlying iterator
+    #[inline]
+    pub fn inner(&self) -> &I {
+        &self.input
+    }
+
     fn next_input_span(&mut self) {
         self.current_span_pos_in_chunk += 1;