Cast delegate to Func in C#

Question

I have code:

public delegate int SomeDelegate(int p);

public static int Inc(int p) {
    return p + 1;
}

I can cast Inc to

Answer 1

The problem is that:

SomeDelegate a = Inc;

Isn't actually a cast. It's the short-form of:

SomeDelegate a = new SomeDelegate(Inc);

Therefore there's no cast. A simple solution to your problem can be this (in C# 3.0)

Func<int,int> f = i=>a(i);

Answer 2

You can hack a cast by using a trick where you use the c# equivalent of a c++ union. The tricky part is the struct with two members that have a [FieldOffset(0)]:

[TestFixture]
public class Demo
{
    public void print(int i)
    {
        Console.WriteLine("Int: "+i);
    }

    private delegate void mydelegate(int i);

    [StructLayout(LayoutKind.Explicit)]
    struct funky
    {
        [FieldOffset(0)]
        public mydelegate a;
        [FieldOffset(0)]
        public System.Action<int> b;
    }

    [Test]
    public void delegatetest()
    {
        System.Action<int> f = print;
        funky myfunky;
        myfunky.a = null;
        myfunky.b = f;

        mydelegate a = myfunky.a;

        a(5);
    }
}