New Enumeration Enhancement: Using the enumeration as a Constructor which takes an Integer

Getting Started
1

In Greg O’Lone’s recent blog posting, he discusses the new enumeration enhancements in Xojo 2021r2. One of the enhancements is the ability to use the enumeration as a Constructor which takes an Integer.

I have attempted to duplicate this new feature with the following code:

Enum SomeEnum // placed inside a Module
Foo = 0
Bar = 1
Baz = 2

Var x as New SomeEnum(2) // Using the enumeration as a Constructor which takes an Integer

If x = SomeEnum.Baz then
// x = SomeEnum.Baz
End if

But I get the following error: “Cannot create an instance of enum Module1.SomeEnum with New because it is not a class.
Var x as New SomeEnum(2)”.

I am using the new Xojo version Xojo 2021r2.
I am sure I am doing something wrong here. Can anyone help?

2

I just tried this myself thinking that it only applied to the new Binary enums, but I get an error that the constructor is protected when I try that. I have a message in to @Greg_O_Lone

Public Enum SomeEnum
One
Two
Three
End Enum

var x as new SomeEnum(2)

image
image2782×422 30.2 KB

3

OK, it looks like the addition of a constructor in the blog post was an error. The constructor is not exposed, so you would use something like the following to cast an integer to an enum value:

var x as SomeEnum = 2
4

When I try that I get the following error " Type mismatch error. Expected enum Module1.SomeEnum, but got Int32".

5

Interesting. I don’t see that. Is your enum scope set to Global? Does it say “Xojo 2021 Release 2” in the bottom-right of the Xojo window?

6

Ah, is your enum set to Binary in the inspector? If I turn off that property then I receive that message.

If you’re not using a Binary enum, then you need to cast:

var x as SomeEnum = SomeEnum(2)
7

You guys saw my blog post: How binary enumeration is implemented in Xojo

Binary Enums are classes and sadly the constructor is private.
Normal enums are just integers with some compiler handling.

8

Yes! That’s the answer! I did not have the enum set to Binary. Thank you!

9

Happy to help! Be sure to mark a Solution so future users who find this via search can go right to it.

10

FWIW, you don’t need to cast it. This will work too:

Var x as SomeEnum = 2
11

John got something like this using that:

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image770×279 60.2 KB

Binary off, shows that. Binary on, no error.