Is it possible iterate over enum (preferable in compile time) or at least check that particular value belong to enum?

On 04/18/2015 01:30 PM, HaraldZealot wrote:
> Is it possible iterate over enum (preferable in compile time) or at
> least check that particular value belong to enum?

EnumMembers:

  http://dlang.org/phobos/std_traits.html#EnumMembers

It returns a "static tuple", meaning that a foreach over those members will be a compile-time foreach. (No loop at all at run-time, the body is unrolled for every member.)

Ali

On Saturday, 18 April 2015 at 20:42:09 UTC, Ali Çehreli wrote:
> On 04/18/2015 01:30 PM, HaraldZealot wrote:
>> Is it possible iterate over enum (preferable in compile time) or at
>> least check that particular value belong to enum?
>
> EnumMembers:
>
>   http://dlang.org/phobos/std_traits.html#EnumMembers
>
> It returns a "static tuple", meaning that a foreach over those members will be a compile-time foreach. (No loop at all at run-time, the body is unrolled for every member.)
>
> Ali

Many thanks

On Saturday, 18 April 2015 at 21:11:28 UTC, HaraldZealot wrote:
> On Saturday, 18 April 2015 at 20:42:09 UTC, Ali Çehreli wrote:
>> On 04/18/2015 01:30 PM, HaraldZealot wrote:
>>> Is it possible iterate over enum (preferable in compile time) or at
>>> least check that particular value belong to enum?
>>
>> EnumMembers:
>>
>>  http://dlang.org/phobos/std_traits.html#EnumMembers
>>
>> It returns a "static tuple", meaning that a foreach over those members will be a compile-time foreach. (No loop at all at run-time, the body is unrolled for every member.)
>>
>> Ali
>
> Many thanks

If you want a dynamic version use

    [EnumMembers!T]

or without enumerator aliases (enumerator value duplicate)

    import std.traits: EnumMembers;
    import std.algorithm: sort, uniq;
    return [EnumMembers!T].sort().uniq;

I've turned this into enumMembers at

https://github.com/nordlow/justd/blob/master/traits_ex.d#L396

This prevents the foreach loop from being inlined. I've had problems with compilation performance with nested foreach-iterating over EnumMembers!T with 100s of elements.