IndexOfAny Benchmark

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Attributes.Jobs;
using BenchmarkDotNet.Configs;
using BenchmarkDotNet.Jobs;
using Microsoft.VisualStudio.ProjectSystem;
using PathHelpers;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

[LegacyJitX86Job, LegacyJitX64Job, RyuJitX64Job]
public class IndexOfAny
{
    public static char[] _array = new char[] { '\\', '/' };
    private const string ShortString = "This is a short string.";
    private const string ShortStringEndingWithChar = "This is a short string./";

    [Params(ShortString, ShortStringEndingWithChar)]
    public string Input { get; set; }

    [Benchmark(Baseline = true)]
    public void IndexOfAny_Baseline()
    {
        for (int i = 0; i < 100000; i++)
        {
            ContainsHelper.IndexOfAny(Input, _array);
        }
    }

    [Benchmark]
    public void IndexOfAny_HandWrittenLoop_HardcodedChars()
    {
        for (int i = 0; i < 100000; i++)
        {
            ContainsHelper.IndexOfAny_HandWrittenLoop_HardcodedChars(Input);
        }
    }

    [Benchmark]
    public void IndexOfAny_HandWrittenLoop()
    {
        for (int i = 0; i < 100000; i++)
        {
            ContainsHelper.IndexOfAny_HandWrittenLoop(Input, _array);
        }
    }
}

internal class ContainsHelper
{
    [MethodImpl(MethodImplOptions.NoInlining)]
    public static int IndexOfAny(string value, char[] array)
    {
        return value.IndexOfAny(array);
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    public static int IndexOfAny_HandWrittenLoop_HardcodedChars(string value)
    {
        for (int i = 0; i < value.Length; i++)
        {
            char c = value[i];

            if (c == '/' || c == '\\')
            {
                return i;
            }
        }

        return -1;
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    public static int IndexOfAny_HandWrittenLoop(string value, char[] array)
    {
        for (int i = 0; i < value.Length; i++)
        {
            char c = value[i];

            foreach (var ch in array)
            {
                if (c == ch)
                    return i;
            }
        }

        return -1;
    }
}

class Program
{
    static void Main(string[] args)
    {
        BenchmarkDotNet.Running.BenchmarkRunner.Run<IndexOfAny>();
    }
}