System.Collections.Immutable 11.0.0-preview.3.26207.106

About

This package provides collections that are thread safe and guaranteed to never change their contents, also known as immutable collections. Like strings, any methods that perform modifications will not change the existing instance but instead return a new instance. For efficiency reasons, the implementation uses a sharing mechanism to ensure that newly created instances share as much data as possible with the previous instance while ensuring that operations have a predictable time complexity.

The System.Collections.Immutable library is built-in as part of the shared framework in .NET Runtime. The package can be installed when you need to use it in other target frameworks.

How to Use

using System.Collections.Immutable;

// Create immutable set of strings
ImmutableHashSet<string> colors = ImmutableHashSet.Create("Red", "Green", "Blue");

// Create a new set by adding and removing items from the original set
ImmutableHashSet<string> colorsModified = colors.Remove("Red").Add("Orange");

foreach (string s in colorsModified)
{
    Console.WriteLine(s);
}

/* Example output:
 Blue
 Green
 Orange
 */

Main Types

The main types provided by this library are:

  • System.Collections.Immutable.ImmutableArray
  • System.Collections.Immutable.ImmutableArray<T>
  • System.Collections.Immutable.ImmutableDictionary
  • System.Collections.Immutable.ImmutableDictionary<TKey,TValue>
  • System.Collections.Immutable.ImmutableHashSet
  • System.Collections.Immutable.ImmutableHashSet<T>
  • System.Collections.Immutable.ImmutableList
  • System.Collections.Immutable.ImmutableList<T>
  • System.Collections.Immutable.ImmutableQueue
  • System.Collections.Immutable.ImmutableQueue<T>
  • System.Collections.Immutable.ImmutableSortedDictionary
  • System.Collections.Immutable.ImmutableSortedDictionary<TKey,TValue>
  • System.Collections.Immutable.ImmutableSortedSet
  • System.Collections.Immutable.ImmutableSortedSet<T>
  • System.Collections.Immutable.ImmutableStack
  • System.Collections.Immutable.ImmutableStack<T>
  • System.Collections.Frozen.FrozenDictionary
  • System.Collections.Frozen.FrozenDictionary<TKey, TValue>
  • System.Collections.Frozen.FrozenSet
  • System.Collections.Frozen.FrozenSet<T>

Additional Documentation

Feedback & Contributing

System.Collections.Immutable is released as open source under the MIT license. Bug reports and contributions are welcome at the GitHub repository.

Showing the top 20 packages that depend on System.Collections.Immutable.

Packages Downloads
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/fb3f812a3e4b7534bef784fa2df1c21d1f67864d.
66
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/ec4841263590f5456e32728d98097e97c1605e22.
66
Grpc.Core
Core C# implementation of gRPC - an RPC library and framework. See project site for more info.
65
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/2c94423e50a72aea8a4962d8722641d06bc88b13
65
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/5905d757a89126ebbcdb383b1a10cadda8c6fdc3.
65
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/205504dfd0f686370cffae5df068024c8a2b427f.
65
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. This package was built from the source at https://github.com/dotnet/roslyn/commit/ec1cde8b77c7bca654888681037f55aa0e62dd19
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. This package was built from the source at https://github.com/dotnet/roslyn/commit/ab56a4a6c32268d925014a3e45ddce61fba715cd
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it.
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/231aeb8be8357239499d45c0574e5a9a8c9174f0.
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/7d47461d2ddd32defbc51c2cf0e75a3fef16c3d7.
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/154af84a603094b52bd08b3366c4448f7481af52.
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/fa8e2c9b566e4471a3509fc63d7baca0a2a6d30b.
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/091091276de5136e94e4413faa87e4d4ec3a7671.
64
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/c3b512958589fecf9e847a73db492cfc92f71a69.
63
Microsoft.CodeAnalysis.Common
A shared package used by the Microsoft .NET Compiler Platform ("Roslyn"). Do not install this package manually, it will be added as a prerequisite by other packages that require it. More details at https://aka.ms/roslyn-packages This package was built from the source at https://github.com/dotnet/roslyn/commit/c94e32157c34fa777f674242cd08cfdc98737d62.
63

https://go.microsoft.com/fwlink/?LinkID=799421

.NET Framework 4.6.2

.NET 10.0

  • No dependencies.

.NET 11.0

  • No dependencies.

.NET Standard 2.0

Version Downloads Last updated
11.0.0-preview.5.26302.115 8 06/10/2026
11.0.0-preview.4.26230.115 15 05/13/2026
11.0.0-preview.3.26207.106 21 04/16/2026
11.0.0-preview.2.26159.112 26 03/11/2026
11.0.0-preview.1.26104.118 28 02/12/2026
10.0.9 10 06/10/2026
10.0.8 17 05/13/2026
10.0.7 21 04/24/2026
10.0.6 20 04/16/2026
10.0.5 24 03/12/2026
10.0.4 25 03/11/2026
10.0.3 33 02/12/2026
10.0.2 38 01/16/2026
10.0.1 38 12/12/2025
10.0.0 56 11/14/2025
10.0.0-rc.2.25502.107 65 10/17/2025
10.0.0-rc.1.25451.107 68 09/09/2025
10.0.0-preview.7.25380.108 66 09/05/2025
10.0.0-preview.6.25358.103 64 09/05/2025
10.0.0-preview.5.25277.114 63 09/05/2025
10.0.0-preview.4.25258.110 72 09/05/2025
10.0.0-preview.3.25171.5 65 09/05/2025
10.0.0-preview.2.25163.2 65 09/05/2025
10.0.0-preview.1.25080.5 66 09/05/2025
9.0.17 10 06/10/2026
9.0.16 17 05/13/2026
9.0.15 19 04/16/2026
9.0.14 24 03/11/2026
9.0.13 28 02/12/2026
9.0.12 36 01/17/2026
9.0.11 55 11/15/2025
9.0.10 64 10/18/2025
9.0.9 63 09/09/2025
9.0.8 62 09/05/2025
9.0.7 66 09/05/2025
9.0.6 66 09/05/2025
9.0.5 65 09/05/2025
9.0.4 66 09/05/2025
9.0.3 64 09/05/2025
9.0.2 63 09/05/2025
9.0.1 67 09/05/2025
9.0.0 67 09/05/2025
9.0.0-rc.2.24473.5 65 09/05/2025
9.0.0-rc.1.24431.7 66 09/05/2025
9.0.0-preview.7.24405.7 66 09/05/2025
9.0.0-preview.6.24327.7 63 09/05/2025
9.0.0-preview.5.24306.7 72 09/05/2025
9.0.0-preview.4.24266.19 65 09/05/2025
9.0.0-preview.3.24172.9 66 09/05/2025
9.0.0-preview.2.24128.5 64 09/05/2025
9.0.0-preview.1.24080.9 63 09/05/2025
8.0.0 66 09/05/2025
8.0.0-rc.2.23479.6 67 09/05/2025
8.0.0-rc.1.23419.4 63 09/05/2025
8.0.0-preview.7.23375.6 63 09/05/2025
8.0.0-preview.6.23329.7 64 09/05/2025
8.0.0-preview.5.23280.8 66 09/05/2025
8.0.0-preview.4.23259.5 62 09/05/2025
8.0.0-preview.3.23174.8 67 09/05/2025
8.0.0-preview.2.23128.3 64 09/05/2025
8.0.0-preview.1.23110.8 65 09/05/2025
7.0.0 66 09/05/2025
7.0.0-rc.2.22472.3 64 09/05/2025
7.0.0-rc.1.22426.10 63 09/05/2025
7.0.0-preview.7.22375.6 63 09/05/2025
7.0.0-preview.6.22324.4 65 09/05/2025
7.0.0-preview.5.22301.12 66 09/05/2025
7.0.0-preview.4.22229.4 67 09/05/2025
7.0.0-preview.3.22175.4 65 09/05/2025
7.0.0-preview.2.22152.2 67 09/05/2025
7.0.0-preview.1.22076.8 66 09/05/2025
6.0.1 64 09/05/2025
6.0.0 68 09/05/2025
6.0.0-rc.2.21480.5 65 09/05/2025
6.0.0-rc.1.21451.13 64 09/05/2025
6.0.0-preview.7.21377.19 66 09/05/2025
6.0.0-preview.6.21352.12 71 09/05/2025
6.0.0-preview.5.21301.5 60 09/05/2025
6.0.0-preview.4.21253.7 62 09/05/2025
6.0.0-preview.3.21201.4 64 09/05/2025
6.0.0-preview.2.21154.6 63 09/05/2025
6.0.0-preview.1.21102.12 64 09/05/2025
5.0.0 69 09/05/2025
5.0.0-rc.2.20475.5 64 09/05/2025
5.0.0-rc.1.20451.14 65 09/05/2025
5.0.0-preview.8.20407.11 68 09/05/2025
5.0.0-preview.7.20364.11 66 09/05/2025
5.0.0-preview.6.20305.6 62 09/05/2025
5.0.0-preview.5.20278.1 67 09/05/2025
5.0.0-preview.4.20251.6 66 09/05/2025
5.0.0-preview.3.20214.6 68 09/05/2025
5.0.0-preview.2.20160.6 62 09/05/2025
5.0.0-preview.1.20120.5 66 09/05/2025
1.7.1 66 09/05/2025
1.7.0 65 09/05/2025
1.7.0-preview3.19551.4 64 09/05/2025
1.7.0-preview2.19523.17 60 09/05/2025
1.7.0-preview1.19504.10 63 09/05/2025
1.6.0 69 09/05/2025
1.6.0-rc1.19456.4 65 09/05/2025
1.6.0-preview9.19421.4 64 09/05/2025
1.6.0-preview9.19416.11 62 09/05/2025
1.6.0-preview8.19405.3 49 09/05/2025
1.6.0-preview7.19362.9 61 09/05/2025
1.6.0-preview6.19303.8 65 09/05/2025
1.6.0-preview6.19264.9 68 09/05/2025
1.6.0-preview5.19224.8 61 09/05/2025
1.6.0-preview4.19212.13 66 09/05/2025
1.6.0-preview3.19128.7 61 09/05/2025
1.6.0-preview.19073.11 64 09/05/2025
1.6.0-preview.18571.3 67 09/05/2025
1.5.0 66 09/05/2025
1.5.0-rc1 66 09/05/2025
1.5.0-preview2-26406-04 68 09/05/2025
1.5.0-preview1-26216-02 64 09/05/2025
1.4.0 64 09/05/2025
1.4.0-preview2-25405-01 65 09/05/2025
1.4.0-preview1-25305-02 71 09/05/2025
1.3.1 64 09/05/2025
1.3.0 67 09/05/2025
1.3.0-preview1-24530-04 67 09/05/2025
1.2.0 66 09/05/2025
1.2.0-rc2-24027 64 09/05/2025
1.1.38-beta-23516 64 09/05/2025
1.1.38-beta-23409 63 09/05/2025
1.1.38-beta-23225 51 09/05/2025
1.1.37 53 09/05/2025
1.1.37-beta-23109 71 09/05/2025
1.1.37-beta-23019 63 09/05/2025
1.1.36 68 09/05/2025
1.1.34-rc 65 09/05/2025
1.1.33-beta 67 09/05/2025
1.1.32-beta 67 09/05/2025