On Mon, 13 Jul 2015 08:01:08 GMT, Sönke Ludwig wrote:

Creating closures can sometimes indeed be tricky when nested scopes are involved, but I have troubles reproducing the errors above. What I have is this: http://dpaste.dzfl.pl/0804d5dbb52f

Is there anything structurally different from what you had?

I adapted your code snippet into a simple vibe project called test:
dub init test vibe.d

In dub.json, seems to be using vibe-d 0.7.19

Here is app.d
https://gist.github.com/gronka/f16b52641de6e481caba

I'm getting the same error when I try to compile 

source/app.d(35): Error: need 'this' for 'm_pass' of type 'RequestPass'

If you just want to mix in code to your class, a slightly cleaner approach would be to use a mixin template: 

// user.d
mixin template UserMethods() {
    void register(HTTPServerRequest req, HTTPServerResponse res)
    {
        // can use m_pass here
    }
}

// bolt.d
class Bolt {
    import bolt.views.user;
    mixin UserMethods!();

    void registerRoutes(URLRouter router)
    {
        router.get("/register", &this.register);
    }
}

Oh - that actually looks great. What I didn't like about mixin(import()) is that I'm pretty sure it would become a huge pain to track down compiling/dependency errors.