[Rust] Add docs for what the boolean return value does for some specific "progress" like callbacks

Still need to add more, consider changing the boolean to an enum that describes it better, so we do not need to copy paste docs around.

1 files changed, 4 insertions, 0 deletions

diff --git a/rust/src/progress.rs b/rust/src/progress.rs
index 5ebf8273..e6897e68 100644
--- a/rust/src/progress.rs
+++ b/rust/src/progress.rs
@@ -2,6 +2,10 @@ use std::ffi::c_void;
 
 pub trait ProgressCallback: Sized {
     type SplitProgressType: SplitProgressBuilder;
+    
+    /// Caller function will call this to report progress.
+    /// 
+    /// Return `false` to tell the caller to stop.
     fn progress(&mut self, progress: usize, total: usize) -> bool;
 
     unsafe extern "C" fn cb_progress_callback(