System.Collections.Immutable by Microsoft

<PackageReference Include="System.Collections.Immutable" Version="9.0.1" />

.NET API 259,376 bytes

 FrozenSet

public static class FrozenSet
Provides a set of initialization methods for instances of the FrozenSet<T> class.
public static FrozenSet<T> Create<T>(ReadOnlySpan<T> source)

Creates a FrozenSet<T> with the specified values.

public static FrozenSet<T> Create<T>(IEqualityComparer<T> equalityComparer, ReadOnlySpan<T> source)

Creates a FrozenSet<T> with the specified values.

public static FrozenSet<T> ToFrozenSet<T>(this IEnumerable<T> source, IEqualityComparer<T> comparer = null)

Creates a FrozenSet<T> with the specified values.