Modify ValueType from extension method?

Question

A few days ago I needed to toggle a bool, and I ended up doing like so:

IsVisible = !IsVisible;

I found that to be the simplest way to archive that functionality. But before doing like the example above, I tried out some different ways.

Mostly about using a extension method. Which in my opinion would make it even simpler, or at least less chars to write.

IsVisible.toggle();

But as a boolean is a value type, the bool that is sent though to the extension method is a copy of the original bool, and not a reference type.

public static void Toggle(this boolean value)
{
    value = !value;
}

Which would do what I needed, but as the boolean getting toggled is a copy of the original boolean the change isn't applied to the original...

I tried putting the ref keyword in front of boolean, but that didn't compile. And I still haven't found a reason for that not compiling, wouldn't that be the perfect functionality for extension methods?

public static void Toggle(this ref boolean value)

I even tried casting the boolean into a object, which in my head would make it into a reference type, and then it would no longer be a copy and the change would get passed back. That didn't work either.

So my question is if it's possible to make a extension pass back changes, or another way to make it even simpler than it already is?

I know it quite possible won't get any simpler or more logical than the top example, but you never know :)

Answer 1

Primitive types are immutable. You'll have to write your calling code like this:

IsVisible = IsVisible.Toggle();

That's the best you can do with extension methods. No way around it.