Specify name of class that static method is defined on

[dtolnay]

Question from @nixbox:

I am trying to use CXX. How do I declare a C++ static method under the cxxbridge extern "C"? More specifically, how can I specify the name of the class that static method is defined on? Would cxx_name take "Class::StaticMethod"?

[dtolnay]

This is not implemented yet but it just came up recently in #447 too. I do not like #[cxx_name = "Class::StaticMethod"] because the common case would be that you want either both sides to be methods or neither side to be a method; cxx_name makes it seem like you're dealing with a method on the C++ side and a free function on the Rust side.

In #447 I proposed:

extern "C++" {
    type Class;

    #[Self = "Class"]
    fn StaticMethod();
}

But for now the workaround is to add a header that contains a shim for the static member function you want to call.

extern "C++" {
    include!("my/shims.h");

    type Class;

    fn Class_StaticMethod();
}

// shims.h
#pragma once
#include "Class.h"

inline void Class_StaticMethod() {
  Class::StaticMethod();
}