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Hash clash in polymorphic variants
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| Date: | -- (:) |
| From: | Stefan Monnier <monnier@i...> |
| Subject: | Re: Hash clash in polymorphic variants |
>> > What I meant was simply that instead of using some fixed hash function,
>> > one could use a perfect hashing function which is optimal for its known
>> > set of inputs, and won't ever generate a collision.
>>
>> The problem is that the set of inputs is not know at compile time, only
>> at link time.
> As I've said in the cited post, the perfect hash generator would have to be
> invoked at link time, which shouldn't be a big deal.
That would require postponing the execution of the hash-function to
link-time or run-time. Run-time is clearly undesirable, and link-time
adds yet-more complexity to the linker.
It's not a bad idea, obviously, but AFAICT the linker currently is kept
very simple.
Stefan