Chaining struct method invocations

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On Monday, 7 September 2015 at 14:12:25 UTC, Bahman Movaqar wrote:
> I need some help understand the behaviour of my code[1].  
> Specifically I have trouble with `add` method on line 79.
>
> My impression is that since it returns `this`, multiple 
> invocations can be chained like `obj.add(X).add(Y).add(Z)`.  
> However the test on line 92 fails and if I do a `writeln`, only 
> "p1" and "p2" records show up.
>
> What am I missing here?  Thanks in advance.
>
> [1] 
> https://github.com/bahmanm/d-etudes/blob/master/source/e002/models.d

You should mark your return type with ref. Structs are value 
types and therefore you return only a copy currently.