Re: [boost] [Tokenmap] A (perfect) hash container library chcked-in to sandbox (RFC)

Subject: Re: [boost] [Tokenmap] A (perfect) hash container library chcked-in to sandbox (RFC)
From: OvermindDL1 (overminddl1_at_[hidden])
Date: 2010-02-21 19:51:25

On Sun, Feb 21, 2010 at 4:44 PM, Andrey Semashev
<andrey.semashev_at_[hidden]> wrote:
> On 21.02.2010 23:59, Slawomir Lisznianski wrote:
>>
>>
>> http://svn.boost.org/svn/boost/sandbox/tokenmap/libs/tokenmap/doc/html/index.html
>>
>> A tokenmap is a data structure that uniquely maps pseudo-random
>> generated keys with elements of the collection.
>>
>> Boost.Tokenmap is a (perfect) hash container library for C++. An
>> important distinction between tokenmap and other dictionary-like
>> containers, such as std::map or Boost.Unordered, is that tokenmap
>> generates keys internally (referred to as "tokens") rather than
>> relying on user to provide them. Specifically, when a new element is
>> inserted into the tokenmap, an apparently random key is returned back
>> to the caller which uniquely maps to the stored element. The returned
>> key can later be used in a very efficient lookup.
>>
>> Although the code and documentation are far from complete, the
>> implementation in the repo is functional and hopefully serves as a
>> basis for further work.
>
> How is it different from having an iterator or a pointer to the inserted
> element?

Because those can get invalidated if the map resizes I would wager...