dan marsden wrote:
Eric Niebler wrote:
Of course, calling deep_copy() in the generator is sub-optimal. Every part of the tree has been deep_copied already except the top-most node. When I find time, I'll write a by_value_generator which makes sure everything in the tree is held by value.
Cool, I'll keep an eye out for by_value_generator.
OK, by_value_generator is implemented now. Usage is: template<class Expr> struct my_expr; struct my_domain : domain<by_value_generator<generator<my_expr> > > {}; That's two sequenced generators. The first makes sure the child nodes are held by value, then forwards the result to the second, which wraps the new node in my_expr<>. The second generator is optional. -- Eric Niebler Boost Consulting www.boost-consulting.com The Astoria Seminar ==> http://www.astoriaseminar.com