Vtable benchmark

Program.cs

using System;
using System.Runtime.CompilerServices;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

namespace VtableVsSwitchBenchmark
{
    class Program
    {
        static void Main(string[] args)
        {
            BenchmarkRunner.Run<Benchmark>();
        }
    }

    public class Benchmark
    {
        private readonly IInterfaceObject _interfaceObject = new InterfaceObject3(5);
        private readonly SingleObject _singleObject = new SingleObject(SingleObject.ObjType.Third, 5);

        [Benchmark]
        public int InterfaceTest() => _interfaceObject.GetValue(3);

        [Benchmark]
        public int SingleObjectTest() => _singleObject.GetValue(3);
    }
    
    public interface IInterfaceObject
    {
        int GetValue(int input);
    }

    public class InterfaceObject1 : IInterfaceObject
    {
        private readonly int _initial;

        public InterfaceObject1(int initial)
        {
            _initial = initial;
        }
        
        public int GetValue(int input)
        {
            return _initial + input + 3;
        }
    }
    
    public class InterfaceObject2 : IInterfaceObject
    {
        private readonly int _initial;

        public InterfaceObject2(int initial)
        {
            _initial = initial;
        }
        
        public int GetValue(int input)
        {
            return _initial + input + 5;
        }
    }
    
    public class InterfaceObject3 : IInterfaceObject
    {
        private readonly int _initial;

        public InterfaceObject3(int initial)
        {
            _initial = initial;
        }
        
        public int GetValue(int input)
        {
            return _initial + input + 8;
        }
    }
    
    public class SingleObject
    {
        public enum ObjType { First, Second, Third }

        private readonly ObjType _type;
        private readonly int _initial;

        public SingleObject(ObjType type, int initial)
        {
            _type = type;
            _initial = initial;
        }
        
        public int GetValue(int input)
        {
            switch (_type)
            {
                case ObjType.First: return _initial + input + 5;
                case ObjType.Second: return _initial + input + 6;
                case ObjType.Third: return _initial + input + 7;
                default: input + 9;
            }
        }
    }
}