Creating an array of user-defined structs

[brian via Digitalmars-d-learn]

Thanks Adam.

Couple of follow up questions, if you don't mind:

On Sunday, 21 August 2016 at 23:37:38 UTC, Adam D. Ruppe wrote:
>> testStruct[int] testStructArray;
> That's not actually an array per se, that is a key/value map 
> where the keys are ints.
I understand it's a map, but does my syntax not define an 
Associative Array?? https://dlang.org/spec/hash-map.html
That's kinda what I wanted because I want to be able to look up 
the Structs by the value of int.

> Either do a traditional array and copy struct values onto it or 
> do an array of pointers and new them. Which option is bsed 
> depends on the details of what you're doing.

This was a simple example of what I wanted to illustrate the 
problem. What I probably want for my future program state is some 
sort of hash map, as I'll be using this "array" as a lookup table.
So conceptually something like:

userid | username | structs
----------------------------
0001   | brian    | structAboutBrian
0002   | john     | structAboutJohn

I probably want to be able to look up info using either userid, 
or username, but I can settle for one of them
I'm creating the entries during execution of the program, so I 
have no idea how big the structure is going to be. So I wanted 
something dynamic.

I'm a bit of a novice in terms of theoretical comp sci, so I'm 
not sure what data structure would be best suited to something 
like that, or how to implement. Happy to take advice. :)