Export S4 class generator function

[multimeric]

The documentation for setClass explains that the function returns a class generator object, which can be invoked like new, but since it's an actual function it can be accessed via the :: operator, and therefore offers safety and convenience to users. BioConductor do something like this by defining their own constructor functions, but I see the return value of setClass as R's convenient, built-in version of that.

Unfortunately, though, roxygen2 doesn't allow you to export this generator function automatically. If you add an @export to the setClass statement, it only exports the class itself, via exportClass:
R/my_class.R:

#' @export
MyClass = setClass('MyClass', representation(foo='numeric'))

NAMESPACE:

exportClasses(MyClass)

---

If try to later annotate an @export onto the return value, but separately from the exportClass, Roxygen generates a blank export statement:

R/my_class.R:

#' @export
MyClass = setClass('MyClass', representation(foo='numeric'))

#' @export
MyClass

NAMESPACE:

export()
exportClasses(MyClass)

---

The NAMESPACE file that I actually want to be generated is

export(MyClass)
exportClasses(MyClass)

As a package developer, I would appreciate a new tag (say @exportConstructor), to do this automatically, or else some kind of workaround that allows me to generate the above NAMESPACE using Roxygen, instead of adding it manually.

[hadley]

Minimal reprex:

library(roxygen2)

roc_proc_text(namespace_roclet(), "
#' @export
MyClass = setClass('MyClass', representation(foo='numeric'))"
)
#> [1] "exportClasses(MyClass)"

^{Created on 2022-07-10 by the reprex package (v2.0.1)}