var logfunc1:shared_ptr[DLLFunc];
var logfunc2:shared_ptr[DLLFunc];

function init(logfunc1:ref shared_ptr[DLLFunc], logfunc2:ref shared_ptr[DLLFunc]){
    *logfunc1 = shared_ptr::new(DLLFunc::load("stdio", "_print"));
    *logfunc2 = logfunc1;
}

function log(logfunc:ref shared_ptr[DLLFunc], message:string){
    (*logfunc)->invoke(message.get_data());
}

function update_logger(logfunc:ref shared_ptr[DLLFunc], func:ref DLLFunc){
    **logfunc = *func;
}

function main(){
    init(&logfunc1, &logfunc2);

    //borrow for logfunc1 is no more

    // copy is free to borrow global logfunc1
    update_logger(&logfunc2, DLLFunc::load("kyfoo", "_print"));
}

instance Copy DLLFunc {
    function copy(target:out Bar, source:ref Bar){
        target->dllhandle = dup_dll(source->dllhandle);
        log(&logfunc1, "DLL Handle duped");
        target->funchandle = dup_funchandle(
            source->dllhandle,
            source->funchandle,
            target->dllhandle
        );
        log(&logfunc1, "Func Handle duped");
    }
}