9 Iterators library [iterators]

Requires: !is_sentinel

Effects: Equivalent to:

• (2.1)

  If I is a pointer type or if the expression i.operator->() is well-formed, return iter;

• (2.2)

  Otherwise, if the expression *iter is a glvalue:

  auto&& tmp = *iter;
  return addressof(tmp);
  

• (2.3)

  Otherwise, return proxy(*iter); where proxy is the exposition-only class:

  class proxy {               // exposition only
    value_type_t<I> keep_;
    proxy(reference_t<I>&& x)
      : keep_(std::move(x)) {}
  public:
    const value_type_t<I>* operator->() const {
      return addressof(keep_);
    }
  };
  

The expression in the requires clause is equivalent to:

Readable<const I> &&
  (requires(const I& i) { i.operator->(); } ||
   is_reference<reference_t<I>>::value ||
   Constructible<value_type_t<I>, reference_t<I>>)