MARKUS

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace KCOM

{

    public static class Extensions

    {

        public static IEnumerable<TSource> WhereIf<TSource>(this IEnumerable<TSource> source, bool condition, Func<TSource, bool> predicate)

        {

            if (condition)

                return source.Where(predicate);

            else

                return source;

        }

        public static IEnumerable<TSource> WhereIf<TSource>(this IEnumerable<TSource> source, bool condition, Func<TSource, int, bool> predicate)

        {

            if (condition)

                return source.Where(predicate);

            else

                return source;

        }

        public static bool TryItem<TSource>(this IEnumerable<TSource> source, bool condition, Func<TSource, int, bool> predicate, out TSource item)

        {

            bool result = false;

            item = default(TSource);

            if (condition)

            {

                var selectItem = source.Where(predicate);

                if (selectItem.Count() > 0)

                {

                    item = selectItem.First();

                    result = true;

                }

            }

            return result;

        }

        /// <summary>

        /// 

        /// </summary>

        /// <typeparam name="TSource"></typeparam>

        /// <param name="source"></param>

        /// <param name="item"></param>

        /// <returns></returns>

        public static bool TryFrist<TSource>(this List<TSource> source,bool RemoveSource, out TSource item)

        {

            bool result = false;

            item = default(TSource);

            if (source.Count() > 0)

                {

                    var selectItem = source.First();

                    item = selectItem;

                    if (RemoveSource)

                    {

                        source.Remove(selectItem);

                    }

                    result = true;

                }

            return result;

        }

    }

}