jai-like CTFE string formating

[Sönke Ludwig via Digitalmars-d]

Am 13.08.2017 um 20:25 schrieb Stefan Koch:
> On Sunday, 13 August 2017 at 18:20:15 UTC, Sönke Ludwig wrote:
>> I was a bit shocked by this number and performed a little test with 
>> multiple calls to format. Fortunately only the first one takes that 
>> long to compile. For 500 different calls I got about 2ms per call on 
>> Windows (which might get slowed down somewhat by the slow terminal 
>> output):
>>
>>     import std.format;
>>     template T(size_t i) {
>>       static if (i > 0) {
>>         pragma(msg, format("Bye %s %s %s %s %s %s %s %s %s %s",
>>           i, " I ",  "just", " have", " to", " concat",  " a lot",
>>           " of", " strings ...", 9));
>>         enum T = T!(i-1);
>>       } else enum T = 0;
>>     }
>>     enum test = T!500;
> 
> Wouldn't you say that 2ms is still a pretty long time for a function call ?
> 

For this particular function call, yes, but still a lot less scary ;) To 
get some better numbers, can you do a side by side comparison of your 
two versions both executed a few hundred times? If the simplified 
version still turns out considerably faster then there may be some low 
hanging fruits in vibe.d's web/REST modules.