string hash significant speedup

[Johnson Jones via Digitalmars-d-learn]

On Thursday, 10 August 2017 at 20:07:35 UTC, Steven Schveighoffer 
wrote:
> On 8/10/17 3:36 PM, Johnson Jones wrote:
>> when using T[string], hashing is used. Computing the hash is 
>> slow(relatively speaking).
>> 
>> Does D cache the hashes? Strings are immutable so there is 
>> absolutely no reason why the hash ever need to be computed 
>> more than once.
>
> It computes them on insertion, and caches the result in the 
> structure of the hash table.
>
> -S

Thanks. What is the cache size?