OrdinalComparer.cs

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using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Runtime.CompilerServices;
 
namespace System;
 
[Serializable]
[TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
public class OrdinalComparer : StringComparer
{
    private readonly bool _ignoreCase;
 
    internal OrdinalComparer(bool ignoreCase)
    {
        _ignoreCase = ignoreCase;
    }
 
    public override int Compare(string? x, string? y)
    {
        if ((object)x == y)
        {
            return 0;
        }
        if (x == null)
        {
            return -1;
        }
        if (y == null)
        {
            return 1;
        }
        if (_ignoreCase)
        {
            return string.Compare(x, y, StringComparison.OrdinalIgnoreCase);
        }
        return string.CompareOrdinal(x, y);
    }
 
    public override bool Equals(string? x, string? y)
    {
        if ((object)x == y)
        {
            return true;
        }
        if (x == null || y == null)
        {
            return false;
        }
        if (_ignoreCase)
        {
            if (x.Length != y.Length)
            {
                return false;
            }
            return System.Globalization.Ordinal.EqualsIgnoreCase(ref x.GetRawStringData(), ref y.GetRawStringData(), x.Length);
        }
        return x.Equals(y);
    }
 
    public override int GetHashCode(string obj)
    {
        if (obj == null)
        {
            ThrowHelper.ThrowArgumentNullException(ExceptionArgument.obj);
        }
        if (_ignoreCase)
        {
            return obj.GetHashCodeOrdinalIgnoreCase();
        }
        return obj.GetHashCode();
    }
 
    public override bool Equals([NotNullWhen(true)] object? obj)
    {
        if (!(obj is OrdinalComparer ordinalComparer))
        {
            return false;
        }
        return _ignoreCase == ordinalComparer._ignoreCase;
    }
 
    public override int GetHashCode()
    {
        int hashCode = "OrdinalComparer".GetHashCode();
        if (!_ignoreCase)
        {
            return hashCode;
        }
        return ~hashCode;
    }
 
    private protected override bool IsWellKnownOrdinalComparerCore(out bool ignoreCase)
    {
        ignoreCase = _ignoreCase;
        return true;
    }
}