Template method : Generic IEnumerator « Generic « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Generic
3. Generic IEnumerator

/*Quote from: 

Book Accelerated C# 2005
    * By Trey Nash
    * ISBN: 1-59059-717-6
    * 432 pp.
    * Published: Aug 2006
    * Price: $39.99


*/


using System;
using System.Collections.Generic;

public class MyContainer<T> : IEnumerable<T>
{
    public void Add( T item ) {
        impl.Add( item );
    }

    // Converter<TInput, TOutput> is a new delegate type introduced
    // in the .NET Framework that can be wired up to a method that
    // knows how to convert the TInput type into a TOutput type.
    public void Add<R>( MyContainer<R> otherContainer,Converter<R, T> converter ) {
        foreach( R item in otherContainer ) {
            impl.Add( converter(item) );
        }
    }

    public IEnumerator<T> GetEnumerator() {
        foreach( T item in impl ) {
            yield return item;
        }
    }

    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() {
        return GetEnumerator();
    }

    private List<T> impl = new List<T>();
}

public class EntryPoint
{
    static void Main() {
        MyContainer<long> lContainer = new MyContainer<long>();
        MyContainer<int> iContainer = new MyContainer<int>();

        lContainer.Add( 1 );
        lContainer.Add( 2 );
        iContainer.Add( 3 );
        iContainer.Add( 4 );

        lContainer.Add( iContainer,
                        EntryPoint.IntToLongConverter );

        foreach( long l in lContainer ) {
            Console.WriteLine( l );
        }
    }

    static long IntToLongConverter( int i ) {
        return i;
    }
}

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