Something approximately equivalent would be Boosts multi_index with a couple of indexes. using php_array_t = multi_index_container< int64_t,

Something approximately equivalent would be Boosts multi_index with a couple of indexes. using php_array_t = multi_index_container< int64_t, indexed_by< random_access<>, hashed_unique<identity<int64_t>> > >; There are so many design considerations at play though that such a comparison would be pointless.