Hello, I have a short suggestion about the interface for multi_array. It is possible to query a multi_array<T,N> for information about the storage: // queries ... const size_type* shape() const; const index* strides() const; const index* index_bases() const; ... It appears multi_array uses a boost::array internally to store this information, and uses the data() method to return a pointer in the above methods. Wouldn't it be better to return a reference to the array directly: // queries ... const array<size_type, N>& shape() const; const array<index, N>& strides() const; const array<index, N>& index_bases() const; ... With this interface the information about the number of elements of shapes and strides is not lost during the query. -- Anders Edin, Sidec Technologies AB Fogdevreten 2A, 171 77 Stockholm, Sweden Phone: +46850884525, Fax: +46850884522