Seperating class methods in a different module

[helxi via Digitalmars-d-learn]

1. How can I separate class methods from the declaration block? 
And how can I implement them in a separate module?

module frame;
class Test
{
public:
        int x;
        this();
}
Test.this()
{
        x = 34;
} // does not work

In this scenario I would like to take the constructor to a 
different module called "construct".


2. For practice, I want to implement a few containers in native D 
using DUB. The project aims to create libraries for different 
data structures. I'm thinking that I should make packages for 
different containers and have them under source/. For example, 
source/forward_list, source/queue, source/set etc.

Would you like to suggest me a good project structures for this? 
Imagine I am making a package called forward_list. Under the 
directory forward_list/, I have modules.d that imports dedicated 
modules for useful methods like push_back, insert_after, front, 
sort, merge etc. Is it an acceptable practice to declare classes 
in package.d? So it becomes

//module package.d;
class forward_list
{
public:
        int x;
        merge();

        this(){}
        this(int x){ this.x = x; }
}

//module merge.d;
import package.d

forward_list.merge(Object o){
        //..
}