Proposed resolution:

This wording is relative to N4606.

1. In [string.view.template], add constexpr to the assignment operator:

   constexpr basic_string_view& operator=(const basic_string_view&) noexcept = default;
   

2. In [string.view.template], add constexpr to the reverse range functions:

   constexpr const_reverse_iterator rbegin() const noexcept;
   constexpr const_reverse_iterator rend() const noexcept;
   constexpr const_reverse_iterator crbegin() const noexcept;
   constexpr const_reverse_iterator crend() const noexcept;
   

3. In [string.view.iterators], add constexpr to the reverse range functions:

   constexpr const_reverse_iterator rbegin() const noexcept;
   constexpr const_reverse_iterator crbegin() const noexcept;
   

   -6- Returns: const_reverse_iterator(end())

   constexpr const_reverse_iterator rend() const noexcept;
   constexpr const_reverse_iterator crend() const noexcept;
   

   -7- Returns: const_reverse_iterator(begin())

[ Issues processing Telecon 2016-10-7 ]

split off the copy into its' own issue 2780

P0; set what's left to Tentatively Ready

Previous resolution [SUPERSEDED]:

This wording is relative to N4606.

1. In [string.view.template], add constexpr to the assignment operator:

   constexpr basic_string_view& operator=(const basic_string_view&) noexcept = default;
   

2. In [string.view.template], add constexpr to the reverse range functions:

   constexpr const_reverse_iterator rbegin() const noexcept;
   constexpr const_reverse_iterator rend() const noexcept;
   constexpr const_reverse_iterator crbegin() const noexcept;
   constexpr const_reverse_iterator crend() const noexcept;
   

3. In [string.view.iterators], add constexpr to the reverse range functions:

   constexpr const_reverse_iterator rbegin() const noexcept;
   constexpr const_reverse_iterator crbegin() const noexcept;
   

   -6- Returns: const_reverse_iterator(end())

   constexpr const_reverse_iterator rend() const noexcept;
   constexpr const_reverse_iterator crend() const noexcept;
   

   -7- Returns: const_reverse_iterator(begin())

4. In [string.view.template], add constexpr to copy:

   constexpr size_type copy(charT* s, size_type n, size_type pos = 0) const;
   

5. In [string.view.ops], add constexpr to copy:

   constexpr size_type copy(charT* s, size_type n, size_type pos = 0) const;
   

basic_string_view was not updated to account for other library machinery made constexpr in Oulu. Now that reverse_iterator is constexpr there's no reason the reverse range functions can't be. Also, now that we have C++14 relaxed constexpr, we can also take care of the assignment operator and copy.