How to concatenate a tuple of strings at compile time?

[user1205]

On Saturday, 6 January 2018 at 21:38:41 UTC, user1205 wrote:
> On Saturday, 6 January 2018 at 21:35:19 UTC, user1205 wrote:
>> On Saturday, 6 January 2018 at 19:35:33 UTC, paul wrote:
>>> Hi!
>>>
>>> How to concatenate  a tuple of strings at compile time?
>>> [...]
>>
>> Hello, this simple template does the job:
>>
>> ```
>> template staticCat(T...)
>> if (T.length)
>> {
>>     static if (T.length == 1)
>>         enum staticCat = T[0];
>>     else static if (T.length == 2)
>>         alias staticCat = staticCat!(T[0] ~ T[1]);
>>     else static if (T.length > 2)
>>         alias staticCat = staticCat!(T[0] ~ T[1], T[2..$]);
>> }
>>
>> enum elems1 = tuple("foo", "bar");
>> enum elems2 = tuple("0", "1", "2");
>> enum elems3 = tuple("a");
>> ```
>>
>> pragma(msg, staticCat!(elems1.expand));
>> pragma(msg, staticCat!(elems2.expand));
>> pragma(msg, staticCat!(elems3.expand));
>>
>> There might be other solutions, maybe even in std.meta.
>
> There is also this one, less verbose, more efficient (not 
> recursive template instances):
>
> ```
> template staticCat(T...)
> if (T.length)
> {
>     import std.array;
>     enum staticCat = [T].join();
> }
>
> enum elems1 = tuple("foo", "bar");
> enum elems2 = tuple("0", "1", "2");
> enum elems3 = tuple("a");
>
> pragma(msg, staticCat!(elems1.expand));
> pragma(msg, staticCat!(elems2.expand));
> pragma(msg, staticCat!(elems3.expand));
> ```

+1

Yeah i upvote myself. Best solution so far.
Maybe tweak the constraint.