Is there a way to allocate an instance of a class?

[NSExceptional]

I know there's some function like swift_allocObject or something that some other reflection libraries make use of, but I don't see anything like that in this repo

[NSExceptional]

Oh, I see it's actually in there already, but commented out! Why is it commented out?

[NSExceptional]

Gotcha. Shall I make a PR?

[Azoy]

Had some changes last night that I forgot to push: #31

[NSExceptional]

In terms of making it simple to use, it would be simplest if it only took the metadata and not also the size. Doesn't the size come from the metadata anyway?

[Azoy]

So I thought about that and it does make sense to only have a metadata argument because the other two do come directly from it, but there are use cases where one might want to tail allocate other elements that don't appear in the class's fields. First thing that comes to mind are KeyPaths, but I can imagine others can think of other use cases which is why I left the option open.

[NSExceptional]

Well in that case, would an additionalBytes: Int = 0 argument make more sense instead? That way the primary use case requires the least effort. It could also be sizeOverride: Int? = nil or something, anything that allows the caller to just use the default size

Third idea: an enum like this

enum ObjectAllocationSize {
    case default
    case extraBytes(Int)
    case override(Int)
}

swift_allocObject(_ type: Metadata, options: ObjectAllocationSize = .default)