ThreadPond.cs

using System;
using System.Threading;

namespace Example
{
    public static class ThreadPond
    {
        public static void QueueUserWorkItem<T1>(Action<T1> callback, T1 arg1)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            ThreadPool.QueueUserWorkItem(state =>
            {
                callback((T1)state);
            }, arg1);
        }

        public static void QueueUserWorkItem<T1, T2>(Action<T1, T2> callback, T1 arg1, T2 arg2)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            QueueUserWorkItem(tuple =>
            {
                callback(tuple.Item1, tuple.Item2);
            }, new Tuple<T1, T2>(arg1, arg2));
        }

        public static void QueueUserWorkItem<T1, T2, T3>(Action<T1, T2, T3> callback, T1 arg1, T2 arg2, T3 arg3)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            QueueUserWorkItem(tuple =>
            {
                callback(tuple.Item1, tuple.Item2, tuple.Item3);
            }, new Tuple<T1, T2, T3>(arg1, arg2, arg3));
        }

        public static void QueueUserWorkItem<T1, T2, T3, T4>(Action<T1, T2, T3, T4> callback, T1 arg1, T2 arg2, T3 arg3, T4 arg4)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            QueueUserWorkItem(tuple =>
            {
                callback(tuple.Item1, tuple.Item2, tuple.Item3, tuple.Item4);
            }, new Tuple<T1, T2, T3, T4>(arg1, arg2, arg3, arg4));
        }

        public static void QueueUserWorkItem<T1, T2, T3, T4, T5>(Action<T1, T2, T3, T4, T5> callback, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            QueueUserWorkItem(tuple =>
            {
                callback(tuple.Item1, tuple.Item2, tuple.Item3, tuple.Item4, tuple.Item5);
            }, new Tuple<T1, T2, T3, T4, T5>(arg1, arg2, arg3, arg4, arg5));
        }

        public static void QueueUserWorkItem<T1, T2, T3, T4, T5, T6>(Action<T1, T2, T3, T4, T5, T6> callback, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            QueueUserWorkItem(tuple =>
            {
                callback(tuple.Item1, tuple.Item2, tuple.Item3, tuple.Item4, tuple.Item5, tuple.Item6);
            }, new Tuple<T1, T2, T3, T4, T5, T6>(arg1, arg2, arg3, arg4, arg5, arg6));
        }

        public static void QueueUserWorkItem<T1, T2, T3, T4, T5, T6, T7>(Action<T1, T2, T3, T4, T5, T6, T7> callback, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            QueueUserWorkItem(tuple =>
            {
                callback(tuple.Item1, tuple.Item2, tuple.Item3, tuple.Item4, tuple.Item5, tuple.Item6, tuple.Item7);
            }, new Tuple<T1, T2, T3, T4, T5, T6, T7>(arg1, arg2, arg3, arg4, arg5, arg6, arg7));
        }

        public static void QueueUserWorkItem<T1, T2, T3, T4, T5, T6, T7, TRest>(Action<T1, T2, T3, T4, T5, T6, T7, TRest> callback, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, TRest rest)
        {
            if (callback == null) throw new ArgumentNullException(nameof(callback));

            QueueUserWorkItem(tuple =>
            {
                callback(tuple.Item1, tuple.Item2, tuple.Item3, tuple.Item4, tuple.Item5, tuple.Item6, tuple.Item7, tuple.Rest);
            }, new Tuple<T1, T2, T3, T4, T5, T6, T7, TRest>(arg1, arg2, arg3, arg4, arg5, arg6, arg7, rest));
        }
    }
}