How to make AA key a pointer

[ketmar]

Clinton wrote:

> On Monday, 19 February 2018 at 14:55:01 UTC, Clinton wrote:
>> Hi all, I need advice from better developers on this concern.
>>
>> I'm using an AA to reference another array for quicker access:
>>
>> [...]
>
> Sorry, on second look my explanation isn't very clear. I want to know if:
>
> bool[string] myAA;
>
> myAA[contact.id] = true; // Does this copy contact.id or is this a 
> pointer to contact.id?

there is absolutely no reason to copy `string` ever, as it is `immutable`. 
and compiler knows that. anyway, why don't you just check it by writing the 
code first?

	import std.stdio;
	void main () {
		int[string] a;
		string s = "test";
		writefln("%08x", s.ptr);
		a[s] = 666;
		s = "test1";
		writefln("%08x", s.ptr);
		a[s] = 42;
		foreach (string k; a.byKey) writefln("%08x", k.ptr);
	}