System.Collections.Immutable 10.0.4

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
MessagePack
Extremely Fast MessagePack(MsgPack) Serializer for C# (.NET Framework, .NET 6, Unity, Xamarin).
164
Microsoft.Build
This package contains the Microsoft.Build assembly which is used to create, edit, and evaluate MSBuild projects.
164
Microsoft.Build
This package contains the Microsoft.Build assembly which is used to create, edit, and evaluate MSBuild projects.
171
Microsoft.Build
This package contains the Microsoft.Build assembly which is used to create, edit, and evaluate MSBuild projects.
188
Microsoft.Build
This package contains the Microsoft.Build assembly which is used to create, edit, and evaluation MSBuild projects.
163
Microsoft.Build
This package contains the Microsoft.Build assembly which is used to create, edit, and evaluation MSBuild projects.
165
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/6a5a63bbc9f4449d9bd1e95a8f9624939c3ccdc3.
225
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/81d9274600db701a8b08ed8af3fd6b00a775cc33.
213
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/df45061e218c9b5813c5531bc06fb238a23e30f6.
544
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/e091728607ca0fc9efca55ccfb3e59259c6b5a0a.
425
Npgsql
Npgsql is the open source .NET data provider for PostgreSQL.
170
Npgsql
Npgsql is the open source .NET data provider for PostgreSQL.
187
Npgsql
Npgsql is the open source .NET data provider for PostgreSQL.
213
System.Reflection.Metadata
This package provides a low-level .NET (ECMA-335) metadata reader and writer. It's geared for performance and is the ideal choice for building higher-level libraries that intend to provide their own object model, such as compilers. The metadata format is defined by the ECMA-335 - Common Language Infrastructure (CLI) specification. The System.Reflection.Metadata 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.
177
System.Reflection.Metadata
This package provides a low-level .NET (ECMA-335) metadata reader and writer. It's geared for performance and is the ideal choice for building higher-level libraries that intend to provide their own object model, such as compilers. The metadata format is defined by the ECMA-335 - Common Language Infrastructure (CLI) specification. The System.Reflection.Metadata 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.
542
System.Reflection.Metadata
This packages provides a low-level .NET (ECMA-335) metadata reader and writer. It's geared for performance and is the ideal choice for building higher-level libraries that intend to provide their own object model, such as compilers. Commonly Used Types: System.Reflection.Metadata.MetadataReader System.Reflection.PortableExecutable.PEReader System.Reflection.Metadata.Ecma335.MetadataBuilder System.Reflection.PortableExecutable.PEBuilder System.Reflection.PortableExecutable.ManagedPEBuilder
206
System.Reflection.Metadata
This packages provides a low-level .NET (ECMA-335) metadata reader and writer. It's geared for performance and is the ideal choice for building higher-level libraries that intend to provide their own object model, such as compilers. Commonly Used Types: System.Reflection.Metadata.MetadataReader System.Reflection.PortableExecutable.PEReader System.Reflection.Metadata.Ecma335.MetadataBuilder System.Reflection.PortableExecutable.PEBuilder System.Reflection.PortableExecutable.ManagedPEBuilder When using NuGet 3.x this package requires at least version 3.4.
425
System.Reflection.MetadataLoadContext
Provides read-only reflection on assemblies in an isolated context with support for assemblies that have different architectures and runtimes. Commonly Used Types: System.Reflection.MetadataLoadContext System.Reflection.MetadataAssemblyResolver When using NuGet 3.x this package requires at least version 3.4.
166
System.Reflection.MetadataLoadContext
Provides read-only reflection on assemblies in an isolated context with support for assemblies that target different processor architectures and runtimes. Using MetadataLoadContext enables you to inspect assemblies without loading them into the main execution context. Assemblies in MetadataLoadContext are treated only as metadata, that is, you can read information about their members, but cannot execute any code contained in them.
179

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

.NET Framework 4.6.2

.NET 8.0

  • No dependencies.

.NET 9.0

  • No dependencies.

.NET 10.0

  • No dependencies.

.NET Standard 2.0

Version Downloads Last updated
11.0.0-preview.2.26159.112 1 03/12/2026
11.0.0-preview.1.26104.118 10 02/12/2026
10.0.5 1 03/13/2026
10.0.4 1 03/12/2026
10.0.3 13 02/12/2026
10.0.2 12 01/14/2026
10.0.1 36 12/10/2025
10.0.0 47 11/14/2025
10.0.0-rc.2.25502.107 73 10/15/2025
10.0.0-rc.1.25451.107 89 09/10/2025
10.0.0-preview.7.25380.108 84 08/12/2025
10.0.0-preview.6.25358.103 69 07/16/2025
10.0.0-preview.5.25277.114 77 06/10/2025
10.0.0-preview.4.25258.110 100 05/15/2025
10.0.0-preview.3.25171.5 86 04/13/2025
10.0.0-preview.2.25163.2 91 04/02/2025
10.0.0-preview.1.25080.5 86 04/02/2025
9.0.14 1 03/12/2026
9.0.13 11 02/11/2026
9.0.12 13 01/14/2026
9.0.11 52 11/14/2025
9.0.10 60 10/15/2025
9.0.9 59 09/10/2025
9.0.8 87 08/05/2025
9.0.7 80 07/09/2025
9.0.6 96 06/12/2025
9.0.5 101 05/16/2025
9.0.4 102 04/10/2025
9.0.3 107 04/02/2025
9.0.2 92 04/01/2025
9.0.1 109 04/02/2025
9.0.0 91 11/14/2024
9.0.0-rc.2.24473.5 96 10/15/2024
9.0.0-rc.1.24431.7 105 09/19/2024
9.0.0-preview.7.24405.7 96 08/18/2024
9.0.0-preview.6.24327.7 126 07/22/2024
9.0.0-preview.5.24306.7 121 07/22/2024
9.0.0-preview.4.24266.19 119 07/22/2024
9.0.0-preview.3.24172.9 138 07/22/2024
9.0.0-preview.2.24128.5 164 07/22/2024
9.0.0-preview.1.24080.9 108 07/22/2024
8.0.0 164 07/22/2024
8.0.0-rc.2.23479.6 132 07/22/2024
8.0.0-rc.1.23419.4 116 07/22/2024
8.0.0-preview.7.23375.6 120 07/22/2024
8.0.0-preview.6.23329.7 138 07/22/2024
8.0.0-preview.5.23280.8 119 07/22/2024
8.0.0-preview.4.23259.5 105 07/22/2024
8.0.0-preview.3.23174.8 138 07/22/2024
8.0.0-preview.2.23128.3 107 07/22/2024
8.0.0-preview.1.23110.8 141 07/22/2024
7.0.0 543 02/05/2024
7.0.0-rc.2.22472.3 141 07/22/2024
7.0.0-rc.1.22426.10 126 07/22/2024
7.0.0-preview.7.22375.6 132 07/22/2024
7.0.0-preview.6.22324.4 130 07/22/2024
7.0.0-preview.5.22301.12 163 07/22/2024
7.0.0-preview.4.22229.4 127 07/22/2024
7.0.0-preview.3.22175.4 132 07/22/2024
7.0.0-preview.2.22152.2 128 07/22/2024
7.0.0-preview.1.22076.8 142 07/22/2024
6.0.2-mauipre.1.22102.15 120 10/14/2024
6.0.1 91 11/14/2024
6.0.0 326 02/04/2024
6.0.0-rc.2.21480.5 134 07/22/2024
6.0.0-rc.1.21451.13 127 07/22/2024
6.0.0-preview.7.21377.19 114 07/22/2024
6.0.0-preview.6.21352.12 126 07/22/2024
6.0.0-preview.5.21301.5 114 07/22/2024
6.0.0-preview.4.21253.7 154 07/22/2024
6.0.0-preview.3.21201.4 134 07/22/2024
6.0.0-preview.2.21154.6 130 07/22/2024
6.0.0-preview.1.21102.12 112 07/22/2024
5.0.0 416 02/04/2024
5.0.0-rc.2.20475.5 115 07/22/2024
5.0.0-rc.1.20451.14 128 07/22/2024
5.0.0-preview.8.20407.11 131 07/22/2024
5.0.0-preview.7.20364.11 139 07/22/2024
5.0.0-preview.6.20305.6 117 07/22/2024
5.0.0-preview.5.20278.1 123 07/22/2024
5.0.0-preview.4.20251.6 136 07/22/2024
5.0.0-preview.3.20214.6 121 07/22/2024
5.0.0-preview.2.20160.6 120 07/22/2024
5.0.0-preview.1.20120.5 121 07/22/2024
1.7.1 116 07/22/2024
1.7.0 129 07/22/2024
1.7.0-preview3.19551.4 101 07/22/2024
1.7.0-preview2.19523.17 123 07/22/2024
1.7.0-preview1.19504.10 122 07/22/2024
1.6.0 146 07/22/2024
1.6.0-rc1.19456.4 132 07/22/2024
1.6.0-preview9.19421.4 138 07/22/2024
1.6.0-preview9.19416.11 141 07/22/2024
1.6.0-preview8.19405.3 119 07/22/2024
1.6.0-preview7.19362.9 132 07/22/2024
1.6.0-preview6.19303.8 139 07/22/2024
1.6.0-preview6.19264.9 120 07/22/2024
1.6.0-preview5.19224.8 104 07/22/2024
1.6.0-preview4.19212.13 108 07/22/2024
1.6.0-preview3.19128.7 116 07/22/2024
1.6.0-preview.19073.11 121 07/22/2024
1.6.0-preview.18571.3 129 07/22/2024
1.5.0 122 07/22/2024
1.5.0-rc1 138 07/22/2024
1.5.0-preview2-26406-04 119 07/22/2024
1.5.0-preview1-26216-02 119 07/22/2024
1.4.0 133 07/22/2024
1.4.0-preview2-25405-01 129 07/22/2024
1.4.0-preview1-25305-02 131 07/22/2024
1.3.1 137 02/05/2024
1.3.0 118 07/22/2024
1.3.0-preview1-24530-04 135 07/22/2024
1.2.0 127 07/22/2024
1.2.0-rc2-24027 122 07/22/2024
1.1.38-beta-23516 146 07/22/2024
1.1.38-beta-23409 130 07/22/2024
1.1.38-beta-23225 134 07/22/2024
1.1.37 108 07/22/2024
1.1.37-beta-23109 134 07/22/2024
1.1.37-beta-23019 140 07/22/2024
1.1.36 137 07/22/2024
1.1.34-rc 158 07/22/2024
1.1.33-beta 123 07/22/2024
1.1.32-beta 123 07/22/2024