ExtensionsIndexOfT(IEnumerableT, T, IEqualityComparerT) - метод

public static int IndexOf<T>(
	this IEnumerable<T> source,
	T value,
	IEqualityComparer<T> comparer = null
)

<ExtensionAttribute>
Public Shared Function IndexOf(Of T) ( 
	source As IEnumerable(Of T),
	value As T,
	Optional comparer As IEqualityComparer(Of T) = Nothing
) As Integer

public:
[ExtensionAttribute]
generic<typename T>
static int IndexOf(
	IEnumerable<T>^ source, 
	T value, 
	IEqualityComparer<T>^ comparer = nullptr
)

[<ExtensionAttribute>]
static member IndexOf : 
        source : IEnumerable<'T> * 
        value : 'T * 
        ?comparer : IEqualityComparer<'T> 
(* Defaults:
        let _comparer = defaultArg comparer null
*)
-> int