Skip to content

Motions 2019 11 lwg 16: P1870R1 forwarding-range<T> is too subtle #3486

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Nov 24, 2019
Merged

Motions 2019 11 lwg 16: P1870R1 forwarding-range<T> is too subtle #3486

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
a7eae9b
P1870R1 forwarding-range<T> is too subtle
Nov 16, 2019
39665f5
[range.range] Fix example to clarify who/what is being specialized fo…
Nov 16, 2019
bceff41
[range.range] [span.cons] Update remaining uses of removed
zygoloid Nov 24, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 14 additions & 0 deletions papers/nxxxx.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -63,6 +63,20 @@ and after consulting the paper authors and the LWG chair,
the corresponding changes were also applied to
the additional range adaptors listed above.

### LWG motion 16

This paper removed the exposition-only concept *`range-impl`*,
inlining it into its only remaining user, the `range` concept.
However, two uses of *`range-impl`* were left behind.
These have been updated and suitably adjusted
to refer to `range` instead.

LWG motion 13 ([P1394R4](http://wg21.link/p1394r4))
added a couple of new uses of
the exposition-only concept *`forwarding-range`*,
which was removed by this paper.
These uses have been replaced with `safe_range`.

## Feature test macros

The feature test macro `__cpp_nontype_template_parameter_class` has been removed
Expand Down
10 changes: 5 additions & 5 deletions source/containers.tex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10513,6 +10513,9 @@
template<class ElementType, size_t Extent = dynamic_extent>
class span;

template<class ElementType, size_t Extent>
inline constexpr bool enable_safe_range<span<ElementType, Extent>> = true;

// \ref{span.objectrep}, views of object representation
template<class ElementType, size_t Extent>
span<const byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>
Expand Down Expand Up @@ -10625,9 +10628,6 @@
constexpr const_reverse_iterator crbegin() const noexcept;
constexpr const_reverse_iterator crend() const noexcept;

friend constexpr iterator begin(span s) noexcept { return s.begin(); }
friend constexpr iterator end(span s) noexcept { return s.end(); }

private:
pointer data_; // \expos
size_type size_; // \expos
Expand Down Expand Up @@ -10786,7 +10786,7 @@
\item \tcode{extent == dynamic_extent} is \tcode{true}.
\item \tcode{R} satisfies \tcode{ranges::\libconcept{contiguous_range}} and
\tcode{ranges::\libconcept{sized_range}}.
\item Either \tcode{R} satisfies \exposconcept{forwarding-range} or
\item Either \tcode{R} satisfies \libconcept{safe_range} or
\tcode{is_const_v<element_type>} is \tcode{true}.
\item \tcode{remove_cvref_t<R>} is not a specialization of \tcode{span}.
\item \tcode{remove_cvref_t<R>} is not a specialization of \tcode{array}.
Expand All @@ -10805,7 +10805,7 @@
\item \tcode{R} models \tcode{ranges::\libconcept{contiguous_range}} and
\tcode{ranges::\libconcept{sized_range}}.
\item If \tcode{is_const_v<element_type>} is \tcode{false},
\tcode{R} models \exposconcept{forwarding-range}.
\tcode{R} models \libconcept{safe_range}.
\end{itemize}

\pnum
Expand Down
Loading