Implementing operator_plus(Float left, Number right)

I've just started a discussion here about implementing operator_plus(Float, Number) in FloatExtensions

To be quick, I noticed DoubleExtensions provides a method to add a Double and a Number with the operator +. I'd like to have the same for Float implemented like this:

@Pure
public static double operator_plus(Float a, Number b) {
return a + b.doubleValue();
}

But when I do it in my own FloatExtensions class, it does not work (instead of using the method I define, it seems it tries to cast Number to a byte, in order to call another + operator).

So:

• Is there a reason operator_plus(Float, Number) is not defined in FloatExtensions?
• Why is my implementation not working? (Note: if I use, for instance, AtomicDouble instead of Number, it works fine, it fails only when the argument is Number)

Start with FloatExtensions and DoubleExtensions, then read the linked forum discussion to understand why Number dispatch differs from AtomicDouble. Done means deciding whether operator_plus(Float, Number) belongs in FloatExtensions and implementing or documenting the expected + behavior, with relevant project tests updated as appropriate.