25 Ranges library [ranges]

reverse_view takes a bidirectional view and produces another view that iterates the same elements in reverse order.

The name views​::​reverse denotes a range adaptor object ([range.adaptor.object]).

Given a subexpression E, the expression views​::​reverse(E) is expression-equivalent to:

• (2.1)
  If the type of E is a (possibly cv-qualified) specialization of reverse_view, then E.base().
• (2.2)
  Otherwise, if the type of E is cv subrange<reverse_iterator<I>, reverse_iterator<I>, K> for some iterator type I and value K of type subrange_kind,

  • (2.2.1)
    if K is subrange_kind​::​sized, then subrange<I, I, K>(E.end().base(), E.begin().base(), E.size());
  • (2.2.2)
    otherwise, subrange<I, I, K>(E.end().base(), E.begin().base()).

  However, in either case E is evaluated only once.
• (2.3)
  Otherwise, reverse_view{E}.