Question

I wrote this very basic programm to examine what the compiler is doing behind the scenes:

class Program
{
    static void Main(string[] args)
    {
        var increase = Increase();
        Console.WriteLine(increase());
        Console.WriteLine(increase());
        Console.ReadLine();
    }

    static Func<int> Increase()
    {
        int counter = 0;
        return () => counter++;
    }
}

Now when I look at the code with Reflector I do see that the compiler generates a class for my closure like that:

[CompilerGenerated]
private sealed class <>c__DisplayClass1
{
    // Fields
    public int counter;

    // Methods
    public int <Increase>b__0()
    {
        return this.counter++;
    }
}

That’s fine and I’m aware that he needs to do that to handle my closure. However, what I can’t see is how he is actually using this class. I mean I should be able to find code that instantiates “<>c__DisplayClass1” somewhere, am I wrong?

EDIT

If I click on the increase method it looks like that:

private static Func<int> Increase()
{
    int counter = 0;
    return delegate {
        return counter++;
    };
}

Answer 1

You should find it in the Increase method, which I’d expect to have an implementation along these lines:

// Not actually valid C# code because of the names...
static Func<int> Increase()
{
    <>c__DisplayClass1 closure = new c__DisplayClass1();
    closure.counter = 0;
    return new Func<int>(closure.<Increase>b__0);
}

Reflector won’t show you that code unless you turn off its optimization, but it should be there. Either turn off Reflector’s optimization, or use ildasm.