MoreEnumerableChooseT, TResult Method

public static IEnumerable<TResult> Choose<T, TResult>(
	this IEnumerable<T> source,
	Func<T, (bool IsSome, TResult , )> chooser
)

<ExtensionAttribute>
Public Shared Function Choose(Of T, TResult) ( 
	source As IEnumerable(Of T),
	chooser As Func(Of T, (IsSome As Boolean,  As TResult, ))
) As IEnumerable(Of TResult)

public:
[ExtensionAttribute]
generic<typename T, typename TResult>
static IEnumerable<TResult>^ Choose(
	IEnumerable<T>^ source, 
	Func<T, ValueTuple<bool, TResult>>^ chooser
)

[<ExtensionAttribute>]
static member Choose : 
        source : IEnumerable<'T> * 
        chooser : Func<'T, ValueTuple<bool, 'TResult>> -> IEnumerable<'TResult> 

var str = "O,l,2,3,4,S,6,7,B,9";
var xs = str.Split(',').Choose(s => (int.TryParse(s, out var n), n));