(See also post on auto_ptr vs shared_ptr.)
Boost scoped_ptr ++forbids++ copy and assignment whereas aptr permits these 2 accidents to happen.
scptr gives up ownership carefully, via reset, where as aptr does so accidentally and freely.
A const auto_ptr (i am not saying “auto_ptr to const”) is very similar to a scoped_ptr. There’s a small difference — P 13 [[boost]]
 Note some text explicitly says a scoped_ptr can’t be the LHS of assignment due to compilation error.