Meziantou.Polyfill

Source Generator that adds polyfill methods and types. This helps working with multi-targeted projects.

Read more about the project: Polyfills in .NET to ease multi-targeting

Installation

dotnet add package Meziantou.Polyfill

Then, you should see the generated types in the solution explorer

Customization

By default, all needed polyfills are generated. You can configure which polyfills should be generated by editing the .csproj file and adding the following properties:

<PropertyGroup>
  <!-- semicolon-separated or pipe-separated list of name prefix -->
  <!-- Tip: The name of the generated polyfills are available in the generated "Debug.g.cs" file -->
  <MeziantouPolyfill_IncludedPolyfills>T:Type1|T:Type2|M:Member1</MeziantouPolyfill_IncludedPolyfills>
  <MeziantouPolyfill_ExcludedPolyfills>M:System.Diagnostics.</MeziantouPolyfill_ExcludedPolyfills>

  <!-- Optional: Output the generated files to the obj\GeneratedFiles folder  -->
  <EmitCompilerGeneratedFiles>True</EmitCompilerGeneratedFiles>
  <CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GeneratedFiles</CompilerGeneratedFilesOutputPath>
</PropertyGroup>

Supported polyfills

Types

• System.Collections.Generic.PriorityQueue<TElement, TPriority>
• System.Collections.Generic.ReferenceEqualityComparer
• System.Diagnostics.CodeAnalysis.AllowNullAttribute
• System.Diagnostics.CodeAnalysis.DisallowNullAttribute
• System.Diagnostics.CodeAnalysis.DoesNotReturnAttribute
• System.Diagnostics.CodeAnalysis.DoesNotReturnIfAttribute
• System.Diagnostics.CodeAnalysis.DynamicDependencyAttribute
• System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes
• System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembersAttribute
• System.Diagnostics.CodeAnalysis.ExperimentalAttribute
• System.Diagnostics.CodeAnalysis.MaybeNullAttribute
• System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute
• System.Diagnostics.CodeAnalysis.MemberNotNullAttribute
• System.Diagnostics.CodeAnalysis.MemberNotNullWhenAttribute
• System.Diagnostics.CodeAnalysis.NotNullAttribute
• System.Diagnostics.CodeAnalysis.NotNullIfNotNullAttribute
• System.Diagnostics.CodeAnalysis.NotNullWhenAttribute
• System.Diagnostics.CodeAnalysis.RequiresAssemblyFilesAttribute
• System.Diagnostics.CodeAnalysis.RequiresDynamicCodeAttribute
• System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute
• System.Diagnostics.CodeAnalysis.SetsRequiredMembersAttribute
• System.Diagnostics.CodeAnalysis.StringSyntaxAttribute
• System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute
• System.Diagnostics.CodeAnalysis.UnscopedRefAttribute
• System.Diagnostics.StackTraceHiddenAttribute
• System.HashCode
• System.Index
• System.Net.Http.ReadOnlyMemoryContent
• System.Range
• System.Runtime.CompilerServices.AsyncMethodBuilderAttribute
• System.Runtime.CompilerServices.CallerArgumentExpressionAttribute
• System.Runtime.CompilerServices.CollectionBuilderAttribute
• System.Runtime.CompilerServices.CompilerFeatureRequiredAttribute
• System.Runtime.CompilerServices.DisableRuntimeMarshallingAttribute
• System.Runtime.CompilerServices.InterpolatedStringHandlerArgumentAttribute
• System.Runtime.CompilerServices.InterpolatedStringHandlerAttribute
• System.Runtime.CompilerServices.IsExternalInit
• System.Runtime.CompilerServices.ModuleInitializerAttribute
• System.Runtime.CompilerServices.RequiredMemberAttribute
• System.Runtime.CompilerServices.SkipLocalsInitAttribute
• System.Runtime.CompilerServices.TupleElementNamesAttribute
• System.Runtime.InteropServices.SuppressGCTransitionAttribute
• System.Runtime.InteropServices.UnmanagedCallersOnlyAttribute
• System.Runtime.Versioning.ObsoletedOSPlatformAttribute
• System.Runtime.Versioning.RequiresPreviewFeaturesAttribute
• System.Runtime.Versioning.SupportedOSPlatformAttribute
• System.Runtime.Versioning.SupportedOSPlatformGuardAttribute
• System.Runtime.Versioning.TargetPlatformAttribute
• System.Runtime.Versioning.UnsupportedOSPlatformAttribute
• System.Runtime.Versioning.UnsupportedOSPlatformGuardAttribute
• System.Threading.Tasks.TaskToAsyncResult
• System.ValueTuple
• System.ValueTuple<T1>
• System.ValueTuple<T1, T2>
• System.ValueTuple<T1, T2, T3>
• System.ValueTuple<T1, T2, T3, T4>
• System.ValueTuple<T1, T2, T3, T4, T5>
• System.ValueTuple<T1, T2, T3, T4, T5, T6>
• System.ValueTuple<T1, T2, T3, T4, T5, T6, T7>
• System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> where TRest : struct
• System.ITupleInternal

Methods

• System.Collections.Concurrent.ConcurrentDictionary<TKey, TValue>.GetOrAdd<TArg>(TKey key, System.Func<TKey, TArg, TValue> valueFactory, TArg factoryArgument)
• System.Collections.Generic.CollectionExtensions.GetValueOrDefault<TKey, TValue>(this System.Collections.Generic.IReadOnlyDictionary<TKey, TValue> dictionary, TKey key)
• System.Collections.Generic.CollectionExtensions.GetValueOrDefault<TKey, TValue>(this System.Collections.Generic.IReadOnlyDictionary<TKey, TValue> dictionary, TKey key, TValue defaultValue)
• System.Collections.Generic.KeyValuePair<TKey, TValue>.Deconstruct(out TKey key, out TValue value)
• System.Collections.Generic.Queue<T>.TryDequeue(out T result)
• System.Collections.Immutable.ImmutableArray<T>.AsSpan(System.Int32 start, System.Int32 length)
• System.Collections.Immutable.ImmutableArray<T>.AsSpan(System.Range range)
• System.Diagnostics.Process.WaitForExitAsync([System.Threading.CancellationToken cancellationToken = default])
• System.IO.Stream.Read(System.Span<System.Byte> buffer)
• System.IO.Stream.ReadAsync(System.Memory<System.Byte> buffer, [System.Threading.CancellationToken cancellationToken = default])
• System.IO.Stream.ReadAtLeast(System.Span<System.Byte> buffer, System.Int32 minimumBytes, [System.Boolean throwOnEndOfStream = true])
• System.IO.Stream.ReadAtLeastAsync(System.Memory<System.Byte> buffer, System.Int32 minimumBytes, [System.Boolean throwOnEndOfStream = true], [System.Threading.CancellationToken cancellationToken = default])
• System.IO.Stream.Write(System.ReadOnlySpan<System.Byte> buffer)
• System.IO.Stream.WriteAsync(System.ReadOnlyMemory<System.Byte> buffer, [System.Threading.CancellationToken cancellationToken = default])
• System.IO.StreamReader.ReadLineAsync()
• System.IO.StreamReader.ReadLineAsync(System.Threading.CancellationToken cancellationToken)
• System.IO.TextReader.ReadAsync(System.Memory<System.Char> buffer, [System.Threading.CancellationToken cancellationToken = default])
• System.IO.TextReader.ReadToEndAsync(System.Threading.CancellationToken cancellationToken)
• System.IO.TextWriter.WriteAsync(System.ReadOnlyMemory<System.Char> buffer, [System.Threading.CancellationToken cancellationToken = default])
• System.Linq.Enumerable.AggregateBy<TSource, TKey, TAccumulate>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, System.Func<TKey, TAccumulate> seedSelector, System.Func<TAccumulate, TSource, TAccumulate> func, [System.Collections.Generic.IEqualityComparer<TKey>? keyComparer = null]) where TKey : notnull
• System.Linq.Enumerable.AggregateBy<TSource, TKey, TAccumulate>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, TAccumulate seed, System.Func<TAccumulate, TSource, TAccumulate> func, [System.Collections.Generic.IEqualityComparer<TKey>? keyComparer = null]) where TKey : notnull
• System.Linq.Enumerable.CountBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, [System.Collections.Generic.IEqualityComparer<TKey>? keyComparer = null]) where TKey : notnull
• System.Linq.Enumerable.DistinctBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector)
• System.Linq.Enumerable.DistinctBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer)
• System.Linq.Enumerable.Index<TSource>(this System.Collections.Generic.IEnumerable<TSource> source)
• System.Linq.Enumerable.MaxBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector)
• System.Linq.Enumerable.MaxBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, System.Collections.Generic.IComparer<TKey>? comparer)
• System.Linq.Enumerable.MinBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector)
• System.Linq.Enumerable.MinBy<TSource, TKey>(this System.Collections.Generic.IEnumerable<TSource> source, System.Func<TSource, TKey> keySelector, System.Collections.Generic.IComparer<TKey>? comparer)
• System.Linq.Enumerable.OrderDescending<T>(this System.Collections.Generic.IEnumerable<T> source)
• System.Linq.Enumerable.OrderDescending<T>(this System.Collections.Generic.IEnumerable<T> source, System.Collections.Generic.IComparer<T>? comparer)
• System.Linq.Enumerable.Order<T>(this System.Collections.Generic.IEnumerable<T> source)
• System.Linq.Enumerable.Order<T>(this System.Collections.Generic.IEnumerable<T> source, System.Collections.Generic.IComparer<T>? comparer)
• System.Linq.Enumerable.ToHashSet<TSource>(this System.Collections.Generic.IEnumerable<TSource> source)
• System.Linq.Enumerable.ToHashSet<TSource>(this System.Collections.Generic.IEnumerable<TSource> source, System.Collections.Generic.IEqualityComparer<TSource>? comparer)
• System.Linq.Enumerable.Zip<TFirst, TSecond>(this System.Collections.Generic.IEnumerable<TFirst> first, System.Collections.Generic.IEnumerable<TSecond> second)
• System.MemoryExtensions.AsSpan(this System.String? text, System.Int32 start, System.Int32 length)
• System.MemoryExtensions.CommonPrefixLength<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other)
• System.MemoryExtensions.CommonPrefixLength<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other, System.Collections.Generic.IEqualityComparer<T>? comparer)
• System.MemoryExtensions.CommonPrefixLength<T>(this System.Span<T> span, System.ReadOnlySpan<T> other)
• System.MemoryExtensions.CommonPrefixLength<T>(this System.Span<T> span, System.ReadOnlySpan<T> other, System.Collections.Generic.IEqualityComparer<T>? comparer)
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAnyExcept<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAny<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAny<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>?
• System.MemoryExtensions.ContainsAny<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>?
• System.MemoryExtensions.Contains<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>?
• System.MemoryExtensions.Contains<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>?
• System.MemoryExtensions.IndexOfAnyExcept<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>?
• System.Net.Http.HttpContent.CopyTo(System.IO.Stream stream, System.Net.TransportContext? context, System.Threading.CancellationToken cancellationToken)
• System.Net.Http.HttpContent.CopyToAsync(System.IO.Stream stream)
• System.Net.Http.HttpContent.CopyToAsync(System.IO.Stream stream, System.Net.TransportContext? context)
• System.Net.Http.HttpContent.CopyToAsync(System.IO.Stream stream, System.Net.TransportContext? context, System.Threading.CancellationToken cancellationToken)
• System.Net.Http.HttpContent.CopyToAsync(System.IO.Stream stream, System.Threading.CancellationToken cancellationToken)
• System.Net.Http.HttpContent.ReadAsStream(System.Threading.CancellationToken cancellationToken)
• System.Net.Http.HttpContent.ReadAsStream()
• System.Net.Sockets.UdpClient.Send(System.ReadOnlySpan<System.Byte> datagram, System.Net.IPEndPoint? endPoint)
• System.Net.Sockets.UdpClient.Send(System.ReadOnlySpan<System.Byte> datagram, System.String? hostname, System.Int32 port)
• System.String.Contains(System.Char value)
• System.String.Contains(System.Char value, System.StringComparison comparisonType)
• System.String.Contains(System.String value, System.StringComparison comparisonType)
• System.String.CopyTo(System.Span<System.Char> destination)
• System.String.EndsWith(System.Char value)
• System.String.GetHashCode(System.StringComparison comparisonType)
• System.String.IndexOf(System.Char value, System.StringComparison comparisonType)
• System.String.Replace(System.String oldValue, System.String? newValue, System.StringComparison comparisonType)
• System.String.ReplaceLineEndings(System.String replacementText)
• System.String.ReplaceLineEndings()
• System.String.Split(System.Char separator, System.Int32 count, [System.StringSplitOptions options = System.StringSplitOptions.None])
• System.String.Split(System.Char separator, [System.StringSplitOptions options = System.StringSplitOptions.None])
• System.String.StartsWith(System.Char value)
• System.String.TryCopyTo(System.Span<System.Char> destination)
• System.Text.Encoding.GetString(System.ReadOnlySpan<System.Byte> bytes)
• System.Text.StringBuilder.Append(System.ReadOnlyMemory<System.Char> value)
• System.Text.StringBuilder.Append(System.ReadOnlySpan<System.Char> value)
• System.Text.StringBuilder.AppendJoin(System.Char separator, params System.Object?[] values)
• System.Text.StringBuilder.AppendJoin(System.Char separator, params System.String?[] values)
• System.Text.StringBuilder.AppendJoin(System.String? separator, params System.Object?[] values)
• System.Text.StringBuilder.AppendJoin(System.String? separator, params System.String?[] values)
• System.Text.StringBuilder.AppendJoin<T>(System.Char separator, System.Collections.Generic.IEnumerable<T> values)
• System.Text.StringBuilder.AppendJoin<T>(System.String? separator, System.Collections.Generic.IEnumerable<T> values)
• System.Text.StringBuilder.Replace(System.ReadOnlySpan<System.Char> oldValue, System.ReadOnlySpan<System.Char> newValue)
• System.Text.StringBuilder.Replace(System.ReadOnlySpan<System.Char> oldValue, System.ReadOnlySpan<System.Char> newValue, System.Int32 startIndex, System.Int32 count)
• System.Threading.CancellationTokenSource.CancelAsync()
• System.Threading.Tasks.Task.WaitAsync(System.Threading.CancellationToken cancellationToken)
• System.Threading.Tasks.TaskAsyncEnumerableExtensions.ToBlockingEnumerable<T>(this System.Collections.Generic.IAsyncEnumerable<T> source, [System.Threading.CancellationToken cancellationToken = default])
• System.Type.IsAssignableTo(System.Type? targetType)

Contribution

How to add a new polyfill

• Create a new file named <xml documentation id>.cs in the project Meziantou.Polyfill.Editor
• Run Meziantou.Polyfill.Generator

Notes:

• All files must be self contained. Use a file class if needed.
• If you need to generate a file only when another polyfill is generated, add // when <xml documentation id> in the file