【C#】シーケンスの要素を条件を満たすものと満たさないものに分ける拡張メソッド

ソースコード

using System;
using System.Collections.Generic;

public static class IEnumerableExt
{
    public static Tuple<IEnumerable<T>, IEnumerable<T>> Partition<T>
    (
        this IEnumerable<T> self,
        Func<T, bool>       predicate
    )
    {
        var ok = new List<T>();
        var ng = new List<T>();

        foreach ( var n in self )
        {
            if ( predicate( n ) )
            {
                ok.Add( n );
            }
            else
            {
                ng.Add( n );
            }
        }

        return Tuple.Create( ( IEnumerable<T> ) ok, ( IEnumerable<T> ) ng );
    }
}

使用例1

var list = new[]
{
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
};

var result = list.Partition( c => c % 2 == 0 );

foreach ( var n in result.Item1 )
{
}

foreach ( var n in result.Item2 )
{
}

使用例2

var list = new[]
{
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
};

var ( ok, ng ) = list.Partition( c => c % 2 == 0 );

foreach ( var n in ok )
{
}

foreach ( var n in ng )
{
}

参考サイト様