IInternalStringEqualityComparer.cs

Go to the documentation of this file.

namespace System.Collections.Generic;
 
internal interface IInternalStringEqualityComparer : IEqualityComparer<string>
{
    IEqualityComparer<string> GetUnderlyingEqualityComparer();
 
    internal static IEqualityComparer<string> GetUnderlyingEqualityComparer(IEqualityComparer<string> outerComparer)
    {
        if (outerComparer == null)
        {
            return EqualityComparer<string>.Default;
        }
        if (outerComparer is IInternalStringEqualityComparer internalStringEqualityComparer)
        {
            return internalStringEqualityComparer.GetUnderlyingEqualityComparer();
        }
        return outerComparer;
    }
}