Question

anyone knows a way to solute this smart?

public static void Invert(this ref bool value)
{
    value = !value;
}

c# says i can not use “ref” or “out” within an extension. But such extensions like List.Clear() exist.

Answer 1

List.Clear() isn’t an extension method, it’s a method. And even if it was an extension method, it wouldn’t need to receive the parameter as ref, because it doesn’t “return” a different list than the one you had, it modifies the list.

And, in general, you can’t. But you normally don’t need to.

What about:

public static bool Invert(this bool value)
{
    return !value;
}

bool x = false.Invert();