On Wed, Mar 16, 2011 at 8:23 PM, pavel novikov <paul.cpprules@gmail.com> wrote:
i'm excited to present you a technique which i occasionally invented shared pointers are very good helpers
yes they are. While this topic is hot, I'd like to add a use-case for shared_ptr that is probably not too obvious: Assume the following class interface: // A class that works with points. In order to do so, it requires an accelerator data structure to speed up computations. // Building an accelerator is costly and should be avoided if such an accelerator over the points has already been built. class works_with_points { // Construct from points. Need to generate accelerator. works_with_points (const array_of_points &points) : _acc(new accelarator_over_points(points)) {} // Construct from pre-existing accelerator. // Accelerator is guaranteed to live as long as this class instance does. works_with_points (boost::shared_ptr<accelarator_over_points const> accel) : _acc(accel) {} // Construct from pre-existing accelerator. works_with_points (const accelarator_over_points &accel) : _acc(&accel, null_deleter()) {} private: boost::shared_ptr<accelarator_over_points const> _acc; }; Best regards, Christoph