using System;

using System.Collections;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var objs = new List<object>();

        objs.Add(new Dictionary<string,string>());

        objs.Add("Hello");

        objs.Add(12);

        objs.Add("Steve");

        var appEnum = new StringAppendEnumerable(objs);

​

        foreach (var item in appEnum)

        {

            Console.WriteLine(item);

        }

    }   

}

​

​

public class StringAppendEnumerable : IEnumerable<object>

{

    private IEnumerable<object> _baseEnumerable;

    public StringAppendEnumerable(IEnumerable<object> inputEnumerable)

    {

        _baseEnumerable = inputEnumerable;

    }

    public IEnumerator<object> GetEnumerator() 

    {

        foreach (var obj in _baseEnumerable) 

        {

            if (obj.GetType().FullName == "System.String")

            {

                yield return obj.ToString() + "roxxors";

            }

            else

            {

                yield return obj;

            }

        }

    }

    IEnumerator IEnumerable.GetEnumerator()

    {

        return this.GetEnumerator();

    }

}