#change #notify #track #reactive #watch

archived raii-change-tracker

tracks changes to data and notifies listeners

2 releases

Uses old Rust 2015

0.1.1 Apr 14, 2018
0.1.0 Jul 23, 2017

#17 in #change


95 lines

raii-change-tracker - tracks changes to data and notifies listeners Version Status Doc


Documentation is available here.

Track changes to data and notify listeners.

The main API feature is the DataTracker struct, which takes ownership of a value.

To listen for changes to an instance of the DataTracker struct, the function DataTracker::add_listener() returns a futures::Stream. This Stream is supplied with previous and new values immediately after each change and integrates with the tokio ecosystem.

The principle of operation is that DataTracker::as_tracked_mut() returns a mutable Modifier. Modifier is a RAII scoped guard with two key properties:

  • It implements the DerefMut trait to allow ergonomic access to the underlying data.
  • It implements the Drop trait which checks if the underlying data was changed and, if so, notifies the listeners.

Futhermore, DataTracker::as_ref() returns a (non-mutable) reference to the data for cases when only read-only access to the data is needed.

To implement tracking, when Modifier is created, a copy of the original data is made and when Modifier is dropped, an equality check is performed. If the original and the new data are not equal, the callbacks are called with references to the old and the new values.


Licensed under either of


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Code of conduct

Anyone who interacts with raii-change-tracker in any space including but not limited to this GitHub repository is expected to follow our code of conduct.