Try Get Non Enumerated Count<TSource> Method
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Attempts to determine the number of elements in a sequence without forcing an enumeration.
public: generic <typename TSource> [System::Runtime::CompilerServices::Extension] static bool TryGetNonEnumeratedCount(System::Collections::Generic::IEnumerable<TSource> ^ source, [Runtime::InteropServices::Out] int % count);
public static bool TryGetNonEnumeratedCount<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, out int count);
static member TryGetNonEnumeratedCount : seq<'Source> * int -> bool
<Extension()> Public Function TryGetNonEnumeratedCount(Of TSource) (source As IEnumerable(Of TSource), ByRef count As Integer) As Boolean
The type of the elements of
A sequence that contains elements to be counted.
When this method returns, contains the number of elements in
source, or 0 if the count couldn't be determined without enumeration.
true if the count of
source can be determined without enumeration; otherwise,
The method performs a series of type tests, identifying common subtypes whose count can be determined without enumerating. This includes ICollection<T>, ICollection, and internal types used in the LINQ implementation.
The method is typically a constant-time operation, but ultimately this depends on the complexity characteristics of the underlying collection's implementation.