Re: [Boost-users] Multi Index: Nested std::pair

Subject: Re: [Boost-users] Multi Index: Nested std::pair
From: Etienne Philip Pretorius (icewolfhunter_at_[hidden])
Date: 2009-04-26 21:59:21

Etienne Philip Pretorius wrote:
>>                 /*unique values per x co-ordinate*/
>>                 boost::multi_index::ordered_non_unique<
>>                     boost::multi_index::composite_key<
>>                         element_t,
>>                         boost::multi_index::member<
>>                             element_t,
>>                             unsigned char,
>>                             &element_t::x
>>                         >,
>>                         boost::multi_index::member<
>>                             element_t,
>>                             unsigned char,
>>                             &element_t::value
>>                         >
>>                     >
>>                 >
>>             >
>>         > matrix_t;
>>
>> How would I define the "unique values per x co-ordinate" as there x 
>> co-ordinate is suppose to be non unique while value in this key should 
>> ONLY point to unique instances within that x co-ordinate?
>>
> Would this work?
> 
>                 /*unique values per x co-ordinate*/
>                 boost::multi_index::ordered_unique<
>                     boost::multi_index::composite_key<
>                         element_t,
>                         boost::multi_index::member<
>                             element_t,
>                             unsigned char,
>                             &element_t::x
>                         >,
>                         boost::multi_index::member<
>                             element_t,
>                             unsigned char,
>                             &element_t::value
>                         >
>                     >
>                 >
> 
> As it is not clear in the documentation what the 
> "boost::multi_index::ordered_unique" scope is. IE is it the combination 
> of the defined members (member vs member) of is it based on the first 
> and then on the second (first vs first, second vs second).
> 

The above does not seem to be correct as the algo does not succeed. 
Could someone please give me advise on constructing a key that has 
duplicate ("x" || "y") members while unique "values".

Etienne