enum to flags

[Nicholas Wilson via Digitalmars-d-learn]

On Tuesday, 29 September 2015 at 09:18:52 UTC, John Colvin wrote:
> On Tuesday, 29 September 2015 at 03:31:44 UTC, Nicholas Wilson 
> wrote:
>> so I have a bunch of enums (0 .. n) that i also want to 
>> represent as flags ( 1 << n foreach n ). Is there anyway to do 
>> this other than a string mixin?
>>
>> use like:
>>
>> enum blah
>> {
>>     foo,
>>     bar,
>>     baz,
>> }
>>
>> alias blahFlags = EnumToFlags!blah;
>>
>> static assert(blahFlags.baz == 1 << blah.baz)
>
> Answering a slightly different question, I just wanted to be 
> sure you're aware of this old idiom:
>
> enum blah
> {
>     foo = 0b1;
>     bar = 0b10;
>     baz = 0b100;
>     //and so on...
> }
>
> auto fdsa = blah.foo | blah.baz;
> assert(fdsa & blah.foo);
> assert(fdsa & blah.baz);
> assert(!(fdsa & blah.bar));

I am. The reason I wanted was so i could easily reorder them 
(logical groupings etc. ) .

Nic