AA code 50x slower

[Steven Schveighoffer]

On 2/16/20 7:57 AM, AlphaPurned wrote:
> template AA(string[] S)
> {
>      auto _do() { int[string] d; foreach(s; S) d[s] = 0; return d; }
>      enum AA = _do;

evilrat is 100% correct. Each time you call that if statement, it 
constructs a NEW AA, checks to see if the t parameter is in there, and 
then leaves it for garbage.

In order to fix it, you have to initialize it in a shared static 
constructor (D doesn't currently allow static initialization of runtime 
AAs).

example:

template AA(string[] S)
{
     __gshared const int[string] AA;
     enum _do = (){ int[string] d; foreach(s; S) d[s] = 0; return d; }();
     shared static this()
     {
         AA = _do;
     }
}

-Steve