uniq and array of enum members (That are all strings)

[bauss]

On Wednesday, 16 January 2019 at 16:35:04 UTC, H. S. Teoh wrote:
> On Wed, Jan 16, 2019 at 04:21:12PM +0000, bauss via 
> Digitalmars-d-learn wrote:
>> On Wednesday, 16 January 2019 at 16:12:28 UTC, H. S. Teoh 
>> wrote:
> [...]
>> > .uniq only works on adjacent identical elements.  You should 
>> > sort your array first.
>> > 
>> > If you need to preserve the original order but eliminate 
>> > duplicates, then you could use an AA to keep track of what 
>> > has been seen. E.g.:
>> > 
>> > 	bool[string] seen;
>> > 	auto b = a.filter!((e) {
>> > 			if (e in seen) return false;
>> > 			seen[e] = true;
>> > 			return true;
>> > 		});
> [...]
>> Sorting will not work in my case though because it's an enum 
>> of strings that are not sorted alphabetically.
>> 
>> Right now I'm doing it manually by a foreach in similar way 
>> you're using filter.
>> 
>> I just feel like that's an overkill for something so trivial.
>
> It's not trivial. In order for the computer to know whether or 
> not the i'th element should be excluded, it needs to know what 
> has come before it.

That's not necessarily true.

It just has to know whether the element matches an earlier 
element.

Your filter example demonstrates exactly why sorting isn't 
necessary.