Trait Observer 

pub trait Observer {
    // Provided methods
    fn progress(&mut self, _done: usize, _total: usize) { ... }
    fn output(&mut self, _name: &'static str, _volume: VolumeRef<'_>) { ... }
}

Receives a stage’s progress and its intermediate outputs as they are produced.

Both methods default to doing nothing, so an implementation overrides only what it uses.

Provided Methods

fn progress(&mut self, _done: usize, _total: usize)

Step done of total has started.

fn output(&mut self, _name: &'static str, _volume: VolumeRef<'_>)

An intermediate output named name is ready. The stage documents its names; the slice is only valid for the duration of the call.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl Observer for ()

Ignores progress and outputs.

Implementors

impl<F: FnMut(usize, usize)> Observer for F

A progress callback is an observer that ignores intermediate outputs.