Re: hashed_maps

[Matthew Heaney <matthewjheaney@earthlink.net>]

"Lucretia" <lucretia9@lycos.co.uk> writes:

> Now, I just need to know that what I'm doing with the ordered map
> isn't going to generate a linked list in which the search will end up
> linear as new C++ types are allocated as the key will be the address
> of the C++ instance. Should a hashed map be used, if so, how do you do
> this?  I've only seen examples of hashing with strings.

The container standard guarantees that associative containers must
perform better than O(n), so a linked list would not be an acceptable
implementation.

It's probably quicker and easier to use the ordered map, since the "<"
operator for type Address is declared right there in package System.

If you want to use a hash table, then you can use To_Integer declared in
System.Storage_Elements to implement a hash function for type Adddress.
The generic actual for Equivalent_Keys is just "=".