Re: [Boost-users] composite_key with array member

Uthpal Urubail writes:

I am looking for a container where I have to use 5-10 keys to get the value. I am trying to write something like below.. Can some one help to solve this?

struct entry { int a[10];     int id; };

[...]

typedef multi_index_container<     entry,     indexed_by<     ordered_non_unique<      composite_key<     entry,     member [...]

Not sure if this is what you're looking for, but you can define a global template function extracting the N-th component of entry::a: template<int N> int get_a(const entry& e){return e.a[N];} and then define composite_key on the ten elements of the array as follows: composite_key< entry, global_fun>, global_fun>, global_fun>, global_fun>, global_fun>, global_fun>, global_fun>, global_fun>, global_fun>, global_fun>

Is there any particular reason why you're packing the ten keys in an array 'a' rather than naming them like this? int a0,a1,a2,a3,a4,a5,a6,a7,a8,a9; It'd make thing easier wrt to declaring the composite_key. Joaquín M López Muñoz Telefónica