Question

Does anyone know a trick that would allow me to do something like this (where Function is a Func<bool>:

        UnaryNode<bool> compliment = new UnaryNode<bool>()
            { Function = () => !compliment.Right.Value };

The following works in place, but is not as nice.

        UnaryNode<bool> compliment = new UnaryNode<bool>();
        compliment.Function = () => !compliment.Right.Value;

Answer 1

This is not allowed, as documented in the langauge specification. Section 7.6.10.2:

It is not possible for the object initializer to refer to the newly
created object it is initializing.

Nor do I find your second version in any way not “nice.” As for a “trick,” it would be something even more “ugly.” You would need to create a temporary throwaway, and then rely upon lambdas closing over the variable instead of the value. For example, given:

class Foo
{
    public Func<bool> Function;     
    public Bar Bar;
}

class Bar
{
    public bool Value;
}

You could then have

// DO NOT try this at home
Foo foo = null; 
Foo temp = new Foo { Function = () => !foo.Bar.Value };
foo = temp;

bool result1 = foo.Function(); // true
foo.Bar.Value = true;
bool result2 = foo.Function(); // false

Is that more or less “nice” than what you already have?