[Feature]:

[jbooth88]

Describe the functionality desired 🐞

With the .Sort() method being depreciated there are a couple of rare cases where applying a sort immediately is desired because the properties used in the comparison do not exist downstream.

example:

    changeSet
            .Sort(complexSortComparer) //Sorts on input data type
            .DistinctValues(x => x.Name) //DistinctValues is transforming to Name data type 
            .Bind(out names); //List of names is sorted 

Changing the call chain to use SortAndBind() is not possible in this scenario.

I had a conversation on Slack about this topic:
https://reactivex.slack.com/archives/C4LF8S19N/p1733511277945719

The steps the functionality will provide

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Considerations

SortAndBind

[JakenVeina]

Additional scenarios we discussed...

using var subscription = changes
    .Sort()
    .Transform() // Does not preserve properties needed for sorting
    .Bind()
    .Subscribe();

var sharedChanges = changes
    .Sort()
    .Publish();
    
using var subscription1 = sharedChanges
    .Bind()
    .Subscribe();
    
using var subscription2 = sharedChanges
    .Bind()
    .Subscribe();
    
using var connection = sharedChanges
    .Connect();

The second scenario is pretty compelling to me, as a potential performance improvement for not duplicating sort work. However, I also proposed in the thread that the performance of .Sort() is so poor that one instance of .Sort() might actually NOT be more efficient thant two instances of .SortAndBind(). Now, I'm curious to benchmark it.

[jbooth88]

I think I came across another scenario where there's a use case for sorting before binding. If the output collection is a base type, but the observable stream coming in is a derived type.

If there's an elegant work around I'm not seeing, please let me know :)

protected void example(ISourceCache<DerivedType, int> cache)
{
    cache
        .Connect()
        .Sort(derivedTypeSort)
        .Transform(x => (BseType)x)
        .ObserveOn(uiScheduler)
        .Bind(out collection)
        .Subscribe()
        .DisposeWith(this);
}
private ReadOnlyObservableCollection<BaseType> collection;
public IObservable<SortExpressionComparer<DerivedType>> DerivedTypeSort => //Sort impl