C++ Container equivalents

Brad Roberts braddr at puremagic.com
Wed Aug 15 11:45:09 PDT 2007


On Wed, 15 Aug 2007, Jascha Wetzel wrote:

> Bruce Adams wrote:
> > Hashmap "Unlike DMD's dodgy associative array implementation, it doesn't
> > rely on an ordering comparator"
> > 
> > What's wrong with std.date and whats dodgey about associative arrays?
> 
> what he means is probably that a hash table implementation doesn't need an
> ordering comparator, only equality. D's associative arrays are implemented as
> binary search trees with hash keys as index values. like this it needs both:
> ordering for the tree search and equality due to the non-injective hashing.

Careful, that's not quite correct.  D's builtin associate arrays use a 
binary-tree only for buckets, not for the entire table.  The requirement 
is the same, but the suggestion that it's not a hash table but rather a 
simple binary-tree isn't correct.

Later,
Brad


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