mozilla/rust — pull request #9923 by thestinger (2013-10-18 05:23:53+00:00)
Title: add feature gate for managed boxes

I'll flip this on after doing a snapshot. This syntax may or may not
stay around, and managed boxes are currently not very useful. They have
the same overall performance characteristics as `std::rc::Rc`, but are
significantly slower, allocate larger boxes and hold onto the memory
beyond when it is needed due to lacking move semantics.