ExperimentalEnumerableTrySingleT, TCardinality(IEnumerableT, TCardinality, TCardinality, TCardinality) Method

Returns a tuple with the cardinality of the sequence and the single element in the sequence if it contains exactly one element. similar to SingleTSource(IEnumerableTSource).

Definition

Namespace: MoreLinq.Experimental
Assembly: MoreLinq (in MoreLinq.dll) Version: 4.1.0+0e154ef592f33ce0f6f3d534a9eedee273f0ce72

C#

public static (TCardinality , T ) TrySingle<T, TCardinality>(
	this IEnumerable<T> source,
	TCardinality zero,
	TCardinality one,
	TCardinality many
)

VB

<ExtensionAttribute>
Public Shared Function TrySingle(Of T, TCardinality) ( 
	source As IEnumerable(Of T),
	zero As TCardinality,
	one As TCardinality,
	many As TCardinality
) As ( As TCardinality,  As T)

C++

public:
[ExtensionAttribute]
generic<typename T, typename TCardinality>
static ValueTuple<TCardinality, T> TrySingle(
	IEnumerable<T>^ source, 
	TCardinality zero, 
	TCardinality one, 
	TCardinality many
)

F#

[<ExtensionAttribute>]
static member TrySingle : 
        source : IEnumerable<'T> * 
        zero : 'TCardinality * 
        one : 'TCardinality * 
        many : 'TCardinality -> ValueTuple<'TCardinality, 'T>

Parameters

source IEnumerableT: The source sequence.
zero TCardinality: The value that is returned in the tuple if the sequence has zero elements.
one TCardinality: The value that is returned in the tuple if the sequence has a single element only.
many TCardinality: The value that is returned in the tuple if the sequence has two or more elements.

Type Parameters

T: The type of the elements of source.
TCardinality: The type that expresses cardinality.

Return Value

ValueTupleTCardinality, T
A tuple containing the identified TCardinality and either the single value of T in the sequence or its default value.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerableT. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

This operator uses immediate execution, but never consumes more than two elements from the sequence.