Util.cs

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using System.Collections.Generic;
 
namespace System.Linq.Parallel;
 
internal static class Util
{
    private sealed class FastIntComparer : Comparer<int>
    {
        public override int Compare(int x, int y)
        {
            return x.CompareTo(y);
        }
    }
 
    private sealed class FastLongComparer : Comparer<long>
    {
        public override int Compare(long x, long y)
        {
            return x.CompareTo(y);
        }
    }
 
    private sealed class FastFloatComparer : Comparer<float>
    {
        public override int Compare(float x, float y)
        {
            return x.CompareTo(y);
        }
    }
 
    private sealed class FastDoubleComparer : Comparer<double>
    {
        public override int Compare(double x, double y)
        {
            return x.CompareTo(y);
        }
    }
 
    private sealed class FastDateTimeComparer : Comparer<DateTime>
    {
        public override int Compare(DateTime x, DateTime y)
        {
            return x.CompareTo(y);
        }
    }
 
    private static readonly FastIntComparer s_fastIntComparer = new FastIntComparer();
 
    private static readonly FastLongComparer s_fastLongComparer = new FastLongComparer();
 
    private static readonly FastFloatComparer s_fastFloatComparer = new FastFloatComparer();
 
    private static readonly FastDoubleComparer s_fastDoubleComparer = new FastDoubleComparer();
 
    private static readonly FastDateTimeComparer s_fastDateTimeComparer = new FastDateTimeComparer();
 
    internal static int Sign(int x)
    {
        if (x >= 0)
        {
            if (x != 0)
            {
                return 1;
            }
            return 0;
        }
        return -1;
    }
 
    internal static Comparer<TKey> GetDefaultComparer<TKey>()
    {
        if (typeof(TKey) == typeof(int))
        {
            return (Comparer<TKey>)(object)s_fastIntComparer;
        }
        if (typeof(TKey) == typeof(long))
        {
            return (Comparer<TKey>)(object)s_fastLongComparer;
        }
        if (typeof(TKey) == typeof(float))
        {
            return (Comparer<TKey>)(object)s_fastFloatComparer;
        }
        if (typeof(TKey) == typeof(double))
        {
            return (Comparer<TKey>)(object)s_fastDoubleComparer;
        }
        if (typeof(TKey) == typeof(DateTime))
        {
            return (Comparer<TKey>)(object)s_fastDateTimeComparer;
        }
        return Comparer<TKey>.Default;
    }
}