ConcurrentStack<T> Class

Definition

Namespace:

System.Collections.Concurrent

Assembly:

System.Collections.Concurrent.dll

Source:

ConcurrentStack.cs

Represents a thread-safe last in-first out (LIFO) collection.

generic <typename T>
public ref class ConcurrentStack : System::Collections::Concurrent::IProducerConsumerCollection<T>, System::Collections::Generic::IEnumerable<T>, System::Collections::Generic::IReadOnlyCollection<T>, System::Collections::ICollection

public class ConcurrentStack<T> : System.Collections.Concurrent.IProducerConsumerCollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IReadOnlyCollection<T>, System.Collections.ICollection

type ConcurrentStack<'T> = class
    interface IProducerConsumerCollection<'T>
    interface seq<'T>
    interface IEnumerable
    interface ICollection
    interface IReadOnlyCollection<'T>

Public Class ConcurrentStack(Of T)
Implements ICollection, IEnumerable(Of T), IProducerConsumerCollection(Of T), IReadOnlyCollection(Of T)

Type Parameters

T

The type of the elements contained in the stack.

Inheritance

Object

ConcurrentStack<T>

Implements

IProducerConsumerCollection<T> IEnumerable<T> IReadOnlyCollection<T> ICollection IEnumerable

Examples

The following example shows how to use a ConcurrentStack<T> to push and pop individual items:

using System;
using System.Collections.Concurrent;
using System.Threading.Tasks;

class Example
{
    // Demonstrates:
    //      ConcurrentStack<T>.Push();
    //      ConcurrentStack<T>.TryPeek();
    //      ConcurrentStack<T>.TryPop();
    //      ConcurrentStack<T>.Clear();
    //      ConcurrentStack<T>.IsEmpty;
    static async Task Main()
    {
        int items = 10000;

        ConcurrentStack<int> stack = new ConcurrentStack<int>();

        // Create an action to push items onto the stack
        Action pusher = () =>
        {
            for (int i = 0; i < items; i++)
            {
                stack.Push(i);
            }
        };

        // Run the action once
        pusher();

        if (stack.TryPeek(out int result))
        {
            Console.WriteLine($"TryPeek() saw {result} on top of the stack.");
        }
        else
        {
            Console.WriteLine("Could not peek most recently added number.");
        }

        // Empty the stack
        stack.Clear();

        if (stack.IsEmpty)
        {
            Console.WriteLine("Cleared the stack.");
        }

        // Create an action to push and pop items
        Action pushAndPop = () =>
        {
            Console.WriteLine($"Task started on {Task.CurrentId}");

            int item;
            for (int i = 0; i < items; i++)
                stack.Push(i);
            for (int i = 0; i < items; i++)
                stack.TryPop(out item);

            Console.WriteLine($"Task ended on {Task.CurrentId}");
        };

        // Spin up five concurrent tasks of the action
        var tasks = new Task[5];
        for (int i = 0; i < tasks.Length; i++)
            tasks[i] = Task.Factory.StartNew(pushAndPop);

        // Wait for all the tasks to finish up
        await Task.WhenAll(tasks);

        if (!stack.IsEmpty)
        {
            Console.WriteLine("Did not take all the items off the stack");
        }
    }
}

open System
open System.Collections.Concurrent
open System.Threading.Tasks

// Demonstrates:
//      ConcurrentStack<T>.Push();
//      ConcurrentStack<T>.TryPeek();
//      ConcurrentStack<T>.TryPop();
//      ConcurrentStack<T>.Clear();
//      ConcurrentStack<T>.IsEmpty;

let main =
    task {
        let items = 10000
        let stack = ConcurrentStack<int>()

        // Create an action to push items onto the stack
        let pusher =
            Action(fun () ->
                for i = 0 to items - 1 do
                    stack.Push i)

        // Run the action once
        pusher.Invoke()
        let mutable result = 0

        if stack.TryPeek &result then
            printfn $"TryPeek() saw {result} on top of the stack."
        else
            printfn "Could not peek most recently added number."

        // Empty the stack
        stack.Clear()

        if stack.IsEmpty then
            printfn "Cleared the stack."

        // Create an action to push and pop items
        let pushAndPop =
            Action(fun () ->
                printfn $"Task started on {Task.CurrentId}"

                let mutable item = 0

                for i = 0 to items - 1 do
                    stack.Push i

                for i = 0 to items - 1 do
                    stack.TryPop &item |> ignore

                printfn $"Task ended on {Task.CurrentId}")
        // Spin up five concurrent tasks of the action
        let tasks =
            [| for i = 0 to 4 do
                   Task.Run pushAndPop |]

        // Wait for all the tasks to finish up
        do! Task.WhenAll tasks

        if not stack.IsEmpty then
            printfn "Did not take all the items off the stack"
    }

main.Wait()

Imports System.Collections.Concurrent
Imports System.Threading.Tasks

Class Example
    ' Demonstrates:
    '   ConcurrentStack<T>.Push();
    '   ConcurrentStack<T>.TryPeek();
    '   ConcurrentStack<T>.TryPop();
    '   ConcurrentStack<T>.Clear();
    '   ConcurrentStack<T>.IsEmpty;
    Shared Sub Main()
        Dim items As Integer = 10000
        Dim stack As ConcurrentStack(Of Integer) = New ConcurrentStack(Of Integer)()

        ' Create an action to push items onto the stack
        Dim pusher As Action = Function()
                                   For i As Integer = 0 To items - 1
                                       stack.Push(i)
                                   Next
                               End Function

        ' Run the action once
        pusher()

        Dim result As Integer = Nothing

        If stack.TryPeek(result) Then
            Console.WriteLine($"TryPeek() saw {result} on top of the stack.")
        Else
            Console.WriteLine("Could not peek most recently added number.")
        End If

        ' Empty the stack
        stack.Clear()

        If stack.IsEmpty Then
            Console.WriteLine("Cleared the stack.")
        End If

        ' Create an action to push and pop items
        Dim pushAndPop As Action = Function()
                                       Console.WriteLine($"Task started on {Task.CurrentId}")
                                       Dim item As Integer

                                       For i As Integer = 0 To items - 1
                                           stack.Push(i)
                                       Next

                                       For i As Integer = 0 To items - 1
                                           stack.TryPop(item)
                                       Next

                                       Console.WriteLine($"Task ended on {Task.CurrentId}")
                                   End Function

        ' Spin up five concurrent tasks of the action
        Dim tasks = New Task(4) {}
        For i As Integer = 0 To tasks.Length - 1
            tasks(i) = Task.Factory.StartNew(pushAndPop)
        Next

        ' Wait for all the tasks to finish up
        Task.WaitAll(tasks)

        If Not stack.IsEmpty Then
            Console.WriteLine("Did not take all the items off the stack")
        End If
    End Sub
End Class

The following example shows how to use a ConcurrentStack<T> to push and pop ranges of items:

using System;
using System.Collections.Concurrent;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

class Example
{
    // Demonstrates:
    //      ConcurrentStack<T>.PushRange();
    //      ConcurrentStack<T>.TryPopRange();
    static async Task Main()
    {
        int numParallelTasks = 4;
        int numItems = 1000;
        var stack = new ConcurrentStack<int>();

        // Push a range of values onto the stack concurrently
        await Task.WhenAll(Enumerable.Range(0, numParallelTasks).Select(i => Task.Factory.StartNew((state) =>
        {
            // state = i * numItems
            int index = (int)state;
            int[] array = new int[numItems];
            for (int j = 0; j < numItems; j++)
            {
                array[j] = index + j;
            }

            Console.WriteLine($"Pushing an array of ints from {array[0]} to {array[numItems - 1]}");
            stack.PushRange(array);
        }, i * numItems, CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default)).ToArray());

        int numTotalElements = 4 * numItems;
        int[] resultBuffer = new int[numTotalElements];
        await Task.WhenAll(Enumerable.Range(0, numParallelTasks).Select(i => Task.Factory.StartNew(obj =>
        {
            int index = (int)obj;
            int result = stack.TryPopRange(resultBuffer, index, numItems);

            Console.WriteLine($"TryPopRange expected {numItems}, got {result}.");
        }, i * numItems, CancellationToken.None, TaskCreationOptions.LongRunning, TaskScheduler.Default)).ToArray());

        for (int i = 0; i < numParallelTasks; i++)
        {
            // Create a sequence we expect to see from the stack taking the last number of the range we inserted
            var expected = Enumerable.Range(resultBuffer[i*numItems + numItems - 1], numItems);

            // Take the range we inserted, reverse it, and compare to the expected sequence
            var areEqual = expected.SequenceEqual(resultBuffer.Skip(i * numItems).Take(numItems).Reverse());
            if (areEqual)
            {
                Console.WriteLine($"Expected a range of {expected.First()} to {expected.Last()}. Got {resultBuffer[i * numItems + numItems - 1]} to {resultBuffer[i * numItems]}");
            }
            else
            {
                Console.WriteLine($"Unexpected consecutive ranges.");
            }
        }
    }
}

open System.Collections.Concurrent
open System.Linq
open System.Threading
open System.Threading.Tasks

// Demonstrates:
//      ConcurrentStack<T>.PushRange();
//      ConcurrentStack<T>.TryPopRange();

let main = 
    task {
        let numParallelTasks = 4
        let numItems = 1000
        let stack = ConcurrentStack<int>()

        // Push a range of values onto the stack concurrently
        let! _ = Task.WhenAll(Enumerable.Range(0, numParallelTasks).Select(fun i -> 
            Task.Factory.StartNew((fun state ->
                // state = i * numItems
                let index: int = unbox state
                let array = 
                    [|  for j in 0 .. numItems - 1 do
                            index + j |]
                printfn $"Pushing an array of ints from {array[0]} to {array[numItems - 1]}"
                stack.PushRange array
            ), i * numItems, CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default)).ToArray())

        let numTotalElements = 4 * numItems
        let resultBuffer = Array.zeroCreate numTotalElements
        let! _ = Task.WhenAll(Enumerable.Range(0, numParallelTasks).Select(fun i -> 
            Task.Factory.StartNew((fun obj ->
                let index = unbox obj
                let result = stack.TryPopRange(resultBuffer, index, numItems)
                printfn $"TryPopRange expected {numItems}, got {result}."
            ), i * numItems, CancellationToken.None, TaskCreationOptions.LongRunning, TaskScheduler.Default)).ToArray())

        for i = 0 to numParallelTasks - 1 do
            // Create a sequence we expect to see from the stack taking the last number of the range we inserted
            let expected = Enumerable.Range(resultBuffer[i*numItems + numItems - 1], numItems)

            // Take the range we inserted, reverse it, and compare to the expected sequence
            let areEqual = expected.SequenceEqual(resultBuffer.Skip(i * numItems).Take(numItems).Reverse())
            if areEqual then
                printfn $"Expected a range of {expected.First()} to {expected.Last()}. Got {resultBuffer[i * numItems + numItems - 1]} to {resultBuffer[i * numItems]}"
            else
                printfn $"Unexpected consecutive ranges."
    }
main.Wait()

Imports System.Collections.Concurrent
Imports System.Linq
Imports System.Threading
Imports System.Threading.Tasks

Class Example
    ' Demonstrates:
    '   ConcurrentStack<T>.PushRange();
    '   ConcurrentStack<T>.TryPopRange();
    Shared Sub Main()
        Dim numParallelTasks As Integer = 4
        Dim numItems As Integer = 1000
        Dim stack = New ConcurrentStack(Of Integer)()

        ' Push a range of values onto the stack concurrently
        Task.WaitAll(Enumerable.Range(0, numParallelTasks).[Select](
                     Function(i) Task.Factory.StartNew(
                        Function(state)
                            Dim index As Integer = CInt(state)
                            Dim array As Integer() = New Integer(numItems - 1) {}

                            For j As Integer = 0 To numItems - 1
                                array(j) = index + j
                            Next

                            Console.WriteLine($"Pushing an array of ints from {array(0)} to {array(numItems - 1)}")
                            stack.PushRange(array)
                        End Function, i * numItems, CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.[Default])).ToArray())


        Dim numTotalElements As Integer = 4 * numItems
        Dim resultBuffer As Integer() = New Integer(numTotalElements - 1) {}
        Task.WaitAll(Enumerable.Range(0, numParallelTasks).[Select](
                     Function(i) Task.Factory.StartNew(
                        Function(obj)
                            Dim index As Integer = CInt(obj)
                            Dim result As Integer = stack.TryPopRange(resultBuffer, index, numItems)
                            Console.WriteLine($"TryPopRange expected {numItems}, got {result}.")
                        End Function, i * numItems, CancellationToken.None, TaskCreationOptions.LongRunning, TaskScheduler.[Default])).ToArray())

        For i As Integer = 0 To numParallelTasks - 1
            ' Create a sequence we expect to see from the stack taking the last number of the range we inserted
            Dim expected = Enumerable.Range(resultBuffer(i * numItems + numItems - 1), numItems)

            ' Take the range we inserted, reverse it, and compare to the expected sequence
            Dim areEqual = expected.SequenceEqual(resultBuffer.Skip(i * numItems).Take(numItems).Reverse())

            If areEqual Then
                Console.WriteLine($"Expected a range of {expected.First()} to {expected.Last()}. Got {resultBuffer(i * numItems + numItems - 1)} to {resultBuffer(i * numItems)}")
            Else
                Console.WriteLine($"Unexpected consecutive ranges.")
            End If
        Next
    End Sub
End Class

Remarks

Note

ConcurrentStack<T> implements the IReadOnlyCollection<T> interface starting with the .NET Framework 4.6; in previous versions of the .NET Framework, the ConcurrentStack<T> class did not implement this interface.

ConcurrentStack<T> provides a few main operations:

• Push inserts an element at the top of the ConcurrentStack<T>.

• TryPop removes an element from the top of the ConcurrentStack<T>, or returns false if the item cannot be removed.

• TryPeek returns an element that is at the top of the ConcurrentStack<T> but does not remove it from the ConcurrentStack<T>.

• The TryPopRange and PushRange methods provide efficient pushing and popping of multiple elements in a single operation.

Constructors

ConcurrentStack<T>()	Initializes a new instance of the ConcurrentStack<T> class.
ConcurrentStack<T>(IEnumerable<T>)	Initializes a new instance of the ConcurrentStack<T> class that contains elements copied from the specified collection.

Properties

Count	Gets the number of elements contained in the ConcurrentStack<T>.
IsEmpty	Gets a value that indicates whether the ConcurrentStack<T> is empty.

Methods

Clear()	Removes all objects from the ConcurrentStack<T>.
CopyTo(T[], Int32)	Copies the ConcurrentStack<T> elements to an existing one-dimensional Array, starting at the specified array index.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetEnumerator()	Returns an enumerator that iterates through the ConcurrentStack<T>.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
Push(T)	Inserts an object at the top of the ConcurrentStack<T>.
PushRange(T[])	Inserts multiple objects at the top of the ConcurrentStack<T> atomically.
PushRange(T[], Int32, Int32)	Inserts multiple objects at the top of the ConcurrentStack<T> atomically.
ToArray()	Copies the items stored in the ConcurrentStack<T> to a new array.
ToString()	Returns a string that represents the current object. (Inherited from Object)
TryPeek(T)	Attempts to return an object from the top of the ConcurrentStack<T> without removing it.
TryPop(T)	Attempts to pop and return the object at the top of the ConcurrentStack<T>.
TryPopRange(T[])	Attempts to pop and return multiple objects from the top of the ConcurrentStack<T> atomically.
TryPopRange(T[], Int32, Int32)	Attempts to pop and return multiple objects from the top of the ConcurrentStack<T> atomically.

Explicit Interface Implementations

ICollection.CopyTo(Array, Int32)	Copies the elements of the ICollection to an Array, starting at a particular Array index.
ICollection.IsSynchronized	Gets a value indicating whether access to the ICollection is synchronized with the SyncRoot.
ICollection.SyncRoot	Gets an object that can be used to synchronize access to the ICollection. This property is not supported.
IEnumerable.GetEnumerator()	Returns an enumerator that iterates through a collection.
IProducerConsumerCollection<T>.TryAdd(T)	Attempts to add an object to the IProducerConsumerCollection<T>.
IProducerConsumerCollection<T>.TryTake(T)	Attempts to remove and return an object from the IProducerConsumerCollection<T>.

Extension Methods

ToFrozenDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Creates a FrozenDictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector function.
ToFrozenDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)	Creates a FrozenDictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector and element selector functions.
ToFrozenSet<T>(IEnumerable<T>, IEqualityComparer<T>)	Creates a FrozenSet<T> with the specified values.
ToImmutableArray<TSource>(IEnumerable<TSource>)	Creates an immutable array from the specified collection.
ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Constructs an immutable dictionary from an existing collection of elements, applying a transformation function to the source keys.
ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Constructs an immutable dictionary based on some transformation of a sequence.
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>)	Enumerates and transforms a sequence, and produces an immutable dictionary of its contents.
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>)	Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key comparer.
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>, IEqualityComparer<TValue>)	Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key and value comparers.
ToImmutableHashSet<TSource>(IEnumerable<TSource>)	Enumerates a sequence and produces an immutable hash set of its contents.
ToImmutableHashSet<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>)	Enumerates a sequence, produces an immutable hash set of its contents, and uses the specified equality comparer for the set type.
ToImmutableList<TSource>(IEnumerable<TSource>)	Enumerates a sequence and produces an immutable list of its contents.
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>)	Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents.
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>)	Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key comparer.
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>, IEqualityComparer<TValue>)	Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key and value comparers.
ToImmutableSortedSet<TSource>(IEnumerable<TSource>)	Enumerates a sequence and produces an immutable sorted set of its contents.
ToImmutableSortedSet<TSource>(IEnumerable<TSource>, IComparer<TSource>)	Enumerates a sequence, produces an immutable sorted set of its contents, and uses the specified comparer.
CopyToDataTable<T>(IEnumerable<T>)	Returns a DataTable that contains copies of the DataRow objects, given an input IEnumerable<T> object where the generic parameter T is DataRow.
CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption)	Copies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter T is DataRow.
CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption, FillErrorEventHandler)	Copies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter T is DataRow.
Aggregate<TSource>(IEnumerable<TSource>, Func<TSource,TSource,TSource>)	Applies an accumulator function over a sequence.
Aggregate<TSource,TAccumulate>(IEnumerable<TSource>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>)	Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value.
Aggregate<TSource,TAccumulate,TResult>(IEnumerable<TSource>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>, Func<TAccumulate,TResult>)	Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value, and the specified function is used to select the result value.
All<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Determines whether all elements of a sequence satisfy a condition.
Any<TSource>(IEnumerable<TSource>)	Determines whether a sequence contains any elements.
Any<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Determines whether any element of a sequence satisfies a condition.
Append<TSource>(IEnumerable<TSource>, TSource)	Appends a value to the end of the sequence.
AsEnumerable<TSource>(IEnumerable<TSource>)	Returns the input typed as IEnumerable<T>.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)	Computes the average of a sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Double>)	Computes the average of a sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)	Computes the average of a sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)	Computes the average of a sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)	Computes the average of a sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)	Computes the average of a sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)	Computes the average of a sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)	Computes the average of a sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)	Computes the average of a sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Single>)	Computes the average of a sequence of Single values that are obtained by invoking a transform function on each element of the input sequence.
Cast<TResult>(IEnumerable)	Casts the elements of an IEnumerable to the specified type.
Chunk<TSource>(IEnumerable<TSource>, Int32)	Splits the elements of a sequence into chunks of size at most size.
Concat<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)	Concatenates two sequences.
Contains<TSource>(IEnumerable<TSource>, TSource)	Determines whether a sequence contains a specified element by using the default equality comparer.
Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>)	Determines whether a sequence contains a specified element by using a specified IEqualityComparer<T>.
Count<TSource>(IEnumerable<TSource>)	Returns the number of elements in a sequence.
Count<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns a number that represents how many elements in the specified sequence satisfy a condition.
DefaultIfEmpty<TSource>(IEnumerable<TSource>)	Returns the elements of the specified sequence or the type parameter's default value in a singleton collection if the sequence is empty.
DefaultIfEmpty<TSource>(IEnumerable<TSource>, TSource)	Returns the elements of the specified sequence or the specified value in a singleton collection if the sequence is empty.
Distinct<TSource>(IEnumerable<TSource>)	Returns distinct elements from a sequence by using the default equality comparer to compare values.
Distinct<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>)	Returns distinct elements from a sequence by using a specified IEqualityComparer<T> to compare values.
DistinctBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Returns distinct elements from a sequence according to a specified key selector function.
DistinctBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Returns distinct elements from a sequence according to a specified key selector function and using a specified comparer to compare keys.
ElementAt<TSource>(IEnumerable<TSource>, Index)	Returns the element at a specified index in a sequence.
ElementAt<TSource>(IEnumerable<TSource>, Int32)	Returns the element at a specified index in a sequence.
ElementAtOrDefault<TSource>(IEnumerable<TSource>, Index)	Returns the element at a specified index in a sequence or a default value if the index is out of range.
ElementAtOrDefault<TSource>(IEnumerable<TSource>, Int32)	Returns the element at a specified index in a sequence or a default value if the index is out of range.
Except<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)	Produces the set difference of two sequences by using the default equality comparer to compare values.
Except<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)	Produces the set difference of two sequences by using the specified IEqualityComparer<T> to compare values.
ExceptBy<TSource,TKey>(IEnumerable<TSource>, IEnumerable<TKey>, Func<TSource,TKey>)	Produces the set difference of two sequences according to a specified key selector function.
ExceptBy<TSource,TKey>(IEnumerable<TSource>, IEnumerable<TKey>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Produces the set difference of two sequences according to a specified key selector function.
First<TSource>(IEnumerable<TSource>)	Returns the first element of a sequence.
First<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns the first element in a sequence that satisfies a specified condition.
FirstOrDefault<TSource>(IEnumerable<TSource>)	Returns the first element of a sequence, or a default value if the sequence contains no elements.
FirstOrDefault<TSource>(IEnumerable<TSource>, TSource)	Returns the first element of a sequence, or a specified default value if the sequence contains no elements.
FirstOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.
FirstOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>, TSource)	Returns the first element of the sequence that satisfies a condition, or a specified default value if no such element is found.
GroupBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Groups the elements of a sequence according to a specified key selector function.
GroupBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Groups the elements of a sequence according to a specified key selector function and compares the keys by using a specified comparer.
GroupBy<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)	Groups the elements of a sequence according to a specified key selector function and projects the elements for each group by using a specified function.
GroupBy<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)	Groups the elements of a sequence according to a key selector function. The keys are compared by using a comparer and each group's elements are projected by using a specified function.
GroupBy<TSource,TKey,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TKey,IEnumerable<TSource>,TResult>)	Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key.
GroupBy<TSource,TKey,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TKey,IEnumerable<TSource>,TResult>, IEqualityComparer<TKey>)	Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. The keys are compared by using a specified comparer.
GroupBy<TSource,TKey,TElement,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, Func<TKey,IEnumerable<TElement>,TResult>)	Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. The elements of each group are projected by using a specified function.
GroupBy<TSource,TKey,TElement,TResult>(IEnumerable<TSource>, Func<TSource, TKey>, Func<TSource,TElement>, Func<TKey,IEnumerable<TElement>, TResult>, IEqualityComparer<TKey>)	Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. Key values are compared by using a specified comparer, and the elements of each group are projected by using a specified function.
GroupJoin<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,IEnumerable<TInner>, TResult>)	Correlates the elements of two sequences based on equality of keys and groups the results. The default equality comparer is used to compare keys.
GroupJoin<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,IEnumerable<TInner>, TResult>, IEqualityComparer<TKey>)	Correlates the elements of two sequences based on key equality and groups the results. A specified IEqualityComparer<T> is used to compare keys.
Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)	Produces the set intersection of two sequences by using the default equality comparer to compare values.
Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)	Produces the set intersection of two sequences by using the specified IEqualityComparer<T> to compare values.
IntersectBy<TSource,TKey>(IEnumerable<TSource>, IEnumerable<TKey>, Func<TSource,TKey>)	Produces the set intersection of two sequences according to a specified key selector function.
IntersectBy<TSource,TKey>(IEnumerable<TSource>, IEnumerable<TKey>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Produces the set intersection of two sequences according to a specified key selector function.
Join<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,TInner,TResult>)	Correlates the elements of two sequences based on matching keys. The default equality comparer is used to compare keys.
Join<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,TInner,TResult>, IEqualityComparer<TKey>)	Correlates the elements of two sequences based on matching keys. A specified IEqualityComparer<T> is used to compare keys.
Last<TSource>(IEnumerable<TSource>)	Returns the last element of a sequence.
Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns the last element of a sequence that satisfies a specified condition.
LastOrDefault<TSource>(IEnumerable<TSource>)	Returns the last element of a sequence, or a default value if the sequence contains no elements.
LastOrDefault<TSource>(IEnumerable<TSource>, TSource)	Returns the last element of a sequence, or a specified default value if the sequence contains no elements.
LastOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns the last element of a sequence that satisfies a condition or a default value if no such element is found.
LastOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>, TSource)	Returns the last element of a sequence that satisfies a condition, or a specified default value if no such element is found.
LongCount<TSource>(IEnumerable<TSource>)	Returns an Int64 that represents the total number of elements in a sequence.
LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns an Int64 that represents how many elements in a sequence satisfy a condition.
Max<TSource>(IEnumerable<TSource>)	Returns the maximum value in a generic sequence.
Max<TSource>(IEnumerable<TSource>, IComparer<TSource>)	Returns the maximum value in a generic sequence.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)	Invokes a transform function on each element of a sequence and returns the maximum Decimal value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Double>)	Invokes a transform function on each element of a sequence and returns the maximum Double value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)	Invokes a transform function on each element of a sequence and returns the maximum Int32 value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)	Invokes a transform function on each element of a sequence and returns the maximum Int64 value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)	Invokes a transform function on each element of a sequence and returns the maximum nullable Decimal value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)	Invokes a transform function on each element of a sequence and returns the maximum nullable Double value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)	Invokes a transform function on each element of a sequence and returns the maximum nullable Int32 value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)	Invokes a transform function on each element of a sequence and returns the maximum nullable Int64 value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)	Invokes a transform function on each element of a sequence and returns the maximum nullable Single value.
Max<TSource>(IEnumerable<TSource>, Func<TSource,Single>)	Invokes a transform function on each element of a sequence and returns the maximum Single value.
Max<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>)	Invokes a transform function on each element of a generic sequence and returns the maximum resulting value.
MaxBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Returns the maximum value in a generic sequence according to a specified key selector function.
MaxBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>)	Returns the maximum value in a generic sequence according to a specified key selector function and key comparer.
Min<TSource>(IEnumerable<TSource>)	Returns the minimum value in a generic sequence.
Min<TSource>(IEnumerable<TSource>, IComparer<TSource>)	Returns the minimum value in a generic sequence.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)	Invokes a transform function on each element of a sequence and returns the minimum Decimal value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Double>)	Invokes a transform function on each element of a sequence and returns the minimum Double value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)	Invokes a transform function on each element of a sequence and returns the minimum Int32 value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)	Invokes a transform function on each element of a sequence and returns the minimum Int64 value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)	Invokes a transform function on each element of a sequence and returns the minimum nullable Decimal value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)	Invokes a transform function on each element of a sequence and returns the minimum nullable Double value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)	Invokes a transform function on each element of a sequence and returns the minimum nullable Int32 value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)	Invokes a transform function on each element of a sequence and returns the minimum nullable Int64 value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)	Invokes a transform function on each element of a sequence and returns the minimum nullable Single value.
Min<TSource>(IEnumerable<TSource>, Func<TSource,Single>)	Invokes a transform function on each element of a sequence and returns the minimum Single value.
Min<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>)	Invokes a transform function on each element of a generic sequence and returns the minimum resulting value.
MinBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Returns the minimum value in a generic sequence according to a specified key selector function.
MinBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>)	Returns the minimum value in a generic sequence according to a specified key selector function and key comparer.
OfType<TResult>(IEnumerable)	Filters the elements of an IEnumerable based on a specified type.
Order<T>(IEnumerable<T>)	Sorts the elements of a sequence in ascending order.
Order<T>(IEnumerable<T>, IComparer<T>)	Sorts the elements of a sequence in ascending order.
OrderBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Sorts the elements of a sequence in ascending order according to a key.
OrderBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>)	Sorts the elements of a sequence in ascending order by using a specified comparer.
OrderByDescending<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Sorts the elements of a sequence in descending order according to a key.
OrderByDescending<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>)	Sorts the elements of a sequence in descending order by using a specified comparer.
OrderDescending<T>(IEnumerable<T>)	Sorts the elements of a sequence in descending order.
OrderDescending<T>(IEnumerable<T>, IComparer<T>)	Sorts the elements of a sequence in descending order.
Prepend<TSource>(IEnumerable<TSource>, TSource)	Adds a value to the beginning of the sequence.
Reverse<TSource>(IEnumerable<TSource>)	Inverts the order of the elements in a sequence.
Select<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>)	Projects each element of a sequence into a new form.
Select<TSource,TResult>(IEnumerable<TSource>, Func<TSource,Int32,TResult>)	Projects each element of a sequence into a new form by incorporating the element's index.
SelectMany<TSource,TResult>(IEnumerable<TSource>, Func<TSource,IEnumerable<TResult>>)	Projects each element of a sequence to an IEnumerable<T> and flattens the resulting sequences into one sequence.
SelectMany<TSource,TResult>(IEnumerable<TSource>, Func<TSource,Int32,IEnumerable<TResult>>)	Projects each element of a sequence to an IEnumerable<T>, and flattens the resulting sequences into one sequence. The index of each source element is used in the projected form of that element.
SelectMany<TSource,TCollection,TResult>(IEnumerable<TSource>, Func<TSource,IEnumerable<TCollection>>, Func<TSource,TCollection,TResult>)	Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein.
SelectMany<TSource,TCollection,TResult>(IEnumerable<TSource>, Func<TSource,Int32,IEnumerable<TCollection>>, Func<TSource,TCollection,TResult>)	Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein. The index of each source element is used in the intermediate projected form of that element.
SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)	Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type.
SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)	Determines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>.
Single<TSource>(IEnumerable<TSource>)	Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence.
Single<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.
SingleOrDefault<TSource>(IEnumerable<TSource>)	Returns the only element of a sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.
SingleOrDefault<TSource>(IEnumerable<TSource>, TSource)	Returns the only element of a sequence, or a specified default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.
SingleOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns the only element of a sequence that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition.
SingleOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>, TSource)	Returns the only element of a sequence that satisfies a specified condition, or a specified default value if no such element exists; this method throws an exception if more than one element satisfies the condition.
Skip<TSource>(IEnumerable<TSource>, Int32)	Bypasses a specified number of elements in a sequence and then returns the remaining elements.
SkipLast<TSource>(IEnumerable<TSource>, Int32)	Returns a new enumerable collection that contains the elements from source with the last count elements of the source collection omitted.
SkipWhile<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements.
SkipWhile<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)	Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. The element's index is used in the logic of the predicate function.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)	Computes the sum of the sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>)	Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)	Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)	Computes the sum of the sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)	Computes the sum of the sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)	Computes the sum of the sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)	Computes the sum of the sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)	Computes the sum of the sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)	Computes the sum of the sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence.
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Single>)	Computes the sum of the sequence of Single values that are obtained by invoking a transform function on each element of the input sequence.
Take<TSource>(IEnumerable<TSource>, Int32)	Returns a specified number of contiguous elements from the start of a sequence.
Take<TSource>(IEnumerable<TSource>, Range)	Returns a specified range of contiguous elements from a sequence.
TakeLast<TSource>(IEnumerable<TSource>, Int32)	Returns a new enumerable collection that contains the last count elements from source.
TakeWhile<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Returns elements from a sequence as long as a specified condition is true.
TakeWhile<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)	Returns elements from a sequence as long as a specified condition is true. The element's index is used in the logic of the predicate function.
ToArray<TSource>(IEnumerable<TSource>)	Creates an array from a IEnumerable<T>.
ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function.
ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function and key comparer.
ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)	Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector and element selector functions.
ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)	Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function, a comparer, and an element selector function.
ToHashSet<TSource>(IEnumerable<TSource>)	Creates a HashSet<T> from an IEnumerable<T>.
ToHashSet<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>)	Creates a HashSet<T> from an IEnumerable<T> using the comparer to compare keys.
ToList<TSource>(IEnumerable<TSource>)	Creates a List<T> from an IEnumerable<T>.
ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function.
ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function and key comparer.
ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)	Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to specified key selector and element selector functions.
ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)	Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function, a comparer and an element selector function.
TryGetNonEnumeratedCount<TSource>(IEnumerable<TSource>, Int32)	Attempts to determine the number of elements in a sequence without forcing an enumeration.
Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)	Produces the set union of two sequences by using the default equality comparer.
Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)	Produces the set union of two sequences by using a specified IEqualityComparer<T>.
UnionBy<TSource,TKey>(IEnumerable<TSource>, IEnumerable<TSource>, Func<TSource,TKey>)	Produces the set union of two sequences according to a specified key selector function.
UnionBy<TSource,TKey>(IEnumerable<TSource>, IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Produces the set union of two sequences according to a specified key selector function.
Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)	Filters a sequence of values based on a predicate.
Where<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)	Filters a sequence of values based on a predicate. Each element's index is used in the logic of the predicate function.
Zip<TFirst,TSecond>(IEnumerable<TFirst>, IEnumerable<TSecond>)	Produces a sequence of tuples with elements from the two specified sequences.
Zip<TFirst,TSecond,TThird>(IEnumerable<TFirst>, IEnumerable<TSecond>, IEnumerable<TThird>)	Produces a sequence of tuples with elements from the three specified sequences.
Zip<TFirst,TSecond,TResult>(IEnumerable<TFirst>, IEnumerable<TSecond>, Func<TFirst,TSecond,TResult>)	Applies a specified function to the corresponding elements of two sequences, producing a sequence of the results.
AsParallel(IEnumerable)	Enables parallelization of a query.
AsParallel<TSource>(IEnumerable<TSource>)	Enables parallelization of a query.
AsQueryable(IEnumerable)	Converts an IEnumerable to an IQueryable.
AsQueryable<TElement>(IEnumerable<TElement>)	Converts a generic IEnumerable<T> to a generic IQueryable<T>.
Ancestors<T>(IEnumerable<T>)	Returns a collection of elements that contains the ancestors of every node in the source collection.
Ancestors<T>(IEnumerable<T>, XName)	Returns a filtered collection of elements that contains the ancestors of every node in the source collection. Only elements that have a matching XName are included in the collection.
DescendantNodes<T>(IEnumerable<T>)	Returns a collection of the descendant nodes of every document and element in the source collection.
Descendants<T>(IEnumerable<T>)	Returns a collection of elements that contains the descendant elements of every element and document in the source collection.
Descendants<T>(IEnumerable<T>, XName)	Returns a filtered collection of elements that contains the descendant elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection.
Elements<T>(IEnumerable<T>)	Returns a collection of the child elements of every element and document in the source collection.
Elements<T>(IEnumerable<T>, XName)	Returns a filtered collection of the child elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection.
InDocumentOrder<T>(IEnumerable<T>)	Returns a collection of nodes that contains all nodes in the source collection, sorted in document order.
Nodes<T>(IEnumerable<T>)	Returns a collection of the child nodes of every document and element in the source collection.
Remove<T>(IEnumerable<T>)	Removes every node in the source collection from its parent node.

Thread Safety

All public and protected members of ConcurrentStack<T> are thread-safe and may be used concurrently from multiple threads.

See also

• Thread-Safe Collections