Re: Issue inside upper_bound
av <avhacker@gmail.com> wrote:
1. Comp's operator() always returns true is just to simplify the demo
code. My point is that VC's extra check make the code failed in debug
mode.
The extra checks are actually legal under the current standard.
Heterogeneous search of the kind you attempt is not well defined: the
standard requires the comparator to be a strict weak ordering, and the
definition of the latter talks about comparisons between objects of the
same type. Technically, your predicate is not a strict weak ordering,
and your code is invalid.
Most STL implementation will accept and work correctly for a
heterogeneous search, but your predicate should implement three
overloads of operator(): taking (B, B), (B, A) and (A, B).
Future version of the standard will likely clarify the situation, and
make your code good as written. For more details, see DR270:
http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#270
--
With best wishes,
Igor Tandetnik
With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925