How can i increase max number recursive template expansions?

[John Colvin]

On Sunday, 7 July 2013 at 20:22:59 UTC, Simen Kjaeraas wrote:
> On 2013-07-07, 21:55, QAston wrote:
>
>> I have a large enum in my code (opcodes for a protocol) - 
>> using std.traits.EnumMembers gives me a recursive template 
>> error.
>>
>> How can i increase max number recursive template expansions?
>
> You can't. However, you can amend std.traits.EnumMembers to work
> with larger enums by using this version:
>
>
>
> import std.typetuple;
>
> template EnumMembers(E)
>     if (is(E == enum))
> {
>     // Supply the specified identifier to an constant value.
>     template WithIdentifier(string ident)
>     {
>         static if (ident == "Symbolize")
>         {
>             template Symbolize(alias value)
>             {
>                 enum Symbolize = value;
>             }
>         }
>         else
>         {
>             mixin("template Symbolize(alias "~ ident ~")"
>                  ~"{"
>                      ~"alias "~ ident ~" Symbolize;"
>                  ~"}");
>         }
>     }
>
>     template EnumSpecificMembers(names...)
>     {
>         static if (names.length > 200)
>         {
>             alias TypeTuple!(
>                     EnumSpecificMembers!(names[0..$/2]),
>                     EnumSpecificMembers!(names[$/2..$]),
>                 ) EnumSpecificMembers;
>         }
>         else static if (names.length > 0)
>         {
>             alias TypeTuple!(
>                     WithIdentifier!(names[0])
>                         .Symbolize!(__traits(getMember, E, 
> names[0])),
>                     EnumSpecificMembers!(names[1 .. $]),
>                 ) EnumSpecificMembers;
>         }
>         else
>         {
>             alias TypeTuple!() EnumSpecificMembers;
>         }
>     }
>
>     alias EnumSpecificMembers!(__traits(allMembers, E)) 
> EnumMembers;
> }
>
>
>
> Here, this line:
>         static if (names.length > 200)
> uses divide-and-conquer to reduce the number of template 
> instantiations.

We came up with almost identical solutions, posted within 19 
seconds of each other!