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[2026-03 LWG Motion 14] P3828R1 Rename the to_input view to as_input #8897

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[2026-03 LWG Motion 14] P3828R1 Rename the to_input view to as_input #8897

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82f2817
P3828R1 Rename the to_input view to as_input
jensmaurer Mar 30, 2026
805bb11
fixup: move feature-test macro to the right alphabetical spot
jensmaurer Mar 31, 2026
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76 changes: 38 additions & 38 deletions source/ranges.tex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -562,16 +562,16 @@

namespace views { inline constexpr @\unspec@ cache_latest = @\unspec@; }

// \ref{range.to.input}, to input view
// \ref{range.as.input}, as input view
template<@\libconcept{input_range}@ V>
requires @\libconcept{view}@<V>
class to_input_view;
class as_input_view;

template<class V>
constexpr bool enable_borrowed_range<to_input_view<V>> =
constexpr bool enable_borrowed_range<as_input_view<V>> =
enable_borrowed_range<V>;

namespace views { inline constexpr @\unspec@ to_input = @\unspec@; }
namespace views { inline constexpr @\unspec@ as_input = @\unspec@; }
}

namespace std {
Expand Down Expand Up @@ -17752,12 +17752,12 @@
\tcode{x.\exposid{end_} - y.\exposid{current_}}.
\end{itemdescr}

\rSec2[range.to.input]{To input view}
\rSec2[range.as.input]{As input view}

\rSec3[range.to.input.overview]{Overview}
\rSec3[range.as.input.overview]{Overview}

\pnum
\tcode{to_input_view} presents a view of an underlying sequence
\tcode{as_input_view} presents a view of an underlying sequence
as an input-only non-common range.
\begin{note}
This is useful to avoid overhead
Expand All @@ -17766,36 +17766,36 @@
\end{note}

\pnum
The name \tcode{views::to_input} denotes
The name \tcode{views::as_input} denotes
a range adaptor object\iref{range.adaptor.object}.
Let \tcode{E} be an expression and let \tcode{T} be \tcode{decltype((E))}.
The expression \tcode{views::to_input(E)} is expression-equivalent to:
The expression \tcode{views::as_input(E)} is expression-equivalent to:
\begin{itemize}
\item
\tcode{views::all(E)}
if \tcode{T} models \libconcept{input_range},
does not satisfy \libconcept{common_range}, and
does not satisfy \libconcept{forward_range}.
\item
Otherwise, \tcode{to_input_view(E)}.
Otherwise, \tcode{as_input_view(E)}.
\end{itemize}

\rSec3[range.to.input.view]{Class template \tcode{to_input_view}}
\rSec3[range.as.input.view]{Class template \tcode{as_input_view}}

\indexlibraryglobal{to_input_view}%
\indexlibraryglobal{as_input_view}%
\begin{codeblock}
namespace std::ranges {
template<@\libconcept{input_range}@ V>
requires @\libconcept{view}@<V>
class to_input_view : public view_interface<to_input_view<V>> {
class as_input_view : public view_interface<as_input_view<V>> {
V @\exposid{base_}@ = V(); // \expos

// \ref{range.to.input.iterator}, class template \tcode{to_input_view::\exposid{iterator}}
// \ref{range.as.input.iterator}, class template \tcode{as_input_view::\exposid{iterator}}
template<bool Const> class @\exposid{iterator}@; // \expos

public:
to_input_view() requires @\libconcept{default_initializable}@<V> = default;
constexpr explicit to_input_view(V base);
as_input_view() requires @\libconcept{default_initializable}@<V> = default;
constexpr explicit as_input_view(V base);

constexpr V base() const & requires @\libconcept{copy_constructible}@<V> { return @\exposid{base_}@; }
constexpr V base() && { return std::move(@\exposid{base_}@); }
Expand All @@ -17814,13 +17814,13 @@
};

template<class R>
to_input_view(R&&) -> to_input_view<views::all_t<R>>;
as_input_view(R&&) -> as_input_view<views::all_t<R>>;
}
\end{codeblock}

\indexlibraryctor{to_input_view}%
\indexlibraryctor{as_input_view}%
\begin{itemdecl}
constexpr explicit to_input_view(V base);
constexpr explicit as_input_view(V base);
\end{itemdecl}

\begin{itemdescr}
Expand All @@ -17829,7 +17829,7 @@
Initializes \exposid{base_} with \tcode{std::move(base)}.
\end{itemdescr}

\indexlibrarymember{begin}{to_input_view}%
\indexlibrarymember{begin}{as_input_view}%
\begin{itemdecl}
constexpr auto begin() requires (!@\exposconcept{simple-view}@<V>);
\end{itemdecl}
Expand All @@ -17840,7 +17840,7 @@
Equivalent to: \tcode{return \exposid{iterator}<false>(ranges::begin(\exposid{base_}));}
\end{itemdescr}

\indexlibrarymember{begin}{to_input_view}%
\indexlibrarymember{begin}{as_input_view}%
\begin{itemdecl}
constexpr auto begin() const requires @\libconcept{range}@<const V>;
\end{itemdecl}
Expand All @@ -17851,7 +17851,7 @@
Equivalent to: \tcode{return \exposid{iterator}<true>(ranges::begin(\exposid{base_}));}
\end{itemdescr}

\indexlibrarymember{end}{to_input_view}%
\indexlibrarymember{end}{as_input_view}%
\begin{itemdecl}
constexpr auto end() requires (!@\exposconcept{simple-view}@<V>);
constexpr auto end() const requires @\libconcept{range}@<const V>;
Expand All @@ -17863,7 +17863,7 @@
Equivalent to: \tcode{return ranges::end(\exposid{base_});}
\end{itemdescr}

\indexlibrarymember{size}{to_input_view}%
\indexlibrarymember{size}{as_input_view}%
\begin{itemdecl}
constexpr auto size() requires @\libconcept{sized_range}@<V>;
constexpr auto size() const requires @\libconcept{sized_range}@<const V>;
Expand All @@ -17875,7 +17875,7 @@
Equivalent to: \tcode{return ranges::size(\exposid{base_});}
\end{itemdescr}

\indexlibrarymember{reserve_hint}{to_input_view}%
\indexlibrarymember{reserve_hint}{as_input_view}%
\begin{itemdecl}
constexpr auto reserve_hint() requires @\libconcept{approximately_sized_range}@<V>;
constexpr auto reserve_hint() const requires @\libconcept{approximately_sized_range}@<const V>;
Expand All @@ -17887,15 +17887,15 @@
Equivalent to: \tcode{return ranges::reserve_hint(\exposid{base_});}
\end{itemdescr}

\rSec3[range.to.input.iterator]{Class template \tcode{to_input_view::\exposid{iterator}}}
\rSec3[range.as.input.iterator]{Class template \tcode{as_input_view::\exposid{iterator}}}

\indexlibraryglobal{to_input_view::\exposid{iterator}}%
\indexlibraryglobal{as_input_view::\exposid{iterator}}%
\begin{codeblock}
namespace std::ranges {
template<@\libconcept{input_range}@ V>
requires @\libconcept{view}@<V>
template<bool Const>
class to_input_view<V>::@\exposid{iterator}@ {
class as_input_view<V>::@\exposid{iterator}@ {
using @\exposid{Base}@ = @\exposid{maybe-const}@<Const, V>; // \expos

iterator_t<@\exposid{Base}@> @\exposid{current_}@ = iterator_t<@\exposid{Base}@>(); // \expos
Expand Down Expand Up @@ -17940,7 +17940,7 @@
}
\end{codeblock}

\indexlibraryctor{to_input_view::\exposid{iterator}}%
\indexlibraryctor{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
constexpr explicit @\exposid{iterator}@(iterator_t<@\exposid{Base}@> current);
\end{itemdecl}
Expand All @@ -17951,7 +17951,7 @@
Initializes \exposid{current_} with \tcode{std::move(current)}.
\end{itemdescr}

\indexlibraryctor{to_input_view::\exposid{iterator}}%
\indexlibraryctor{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
constexpr @\exposid{iterator}@(@\exposid{iterator}@<!Const> i)
requires Const && @\libconcept{convertible_to}@<iterator_t<V>, iterator_t<@\exposid{Base}@>>;
Expand All @@ -17963,7 +17963,7 @@
Initializes \exposid{current_} with \tcode{std::move(i.\exposid{current_})}.
\end{itemdescr}

\indexlibrarymember{base}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{base}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
constexpr iterator_t<@\exposid{Base}@> base() &&;
\end{itemdecl}
Expand All @@ -17974,7 +17974,7 @@
\tcode{std::move(\exposid{current_})}.
\end{itemdescr}

\indexlibrarymember{base}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{base}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
constexpr const iterator_t<@\exposid{Base}@>& base() const & noexcept;
\end{itemdecl}
Expand All @@ -17985,7 +17985,7 @@
\exposid{current_}.
\end{itemdescr}

\indexlibrarymember{operator++}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{operator++}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
constexpr @\exposid{iterator}@& operator++();
\end{itemdecl}
Expand All @@ -18000,7 +18000,7 @@
\end{codeblock}
\end{itemdescr}

\indexlibrarymember{operator++}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{operator++}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
constexpr void operator++(int);
\end{itemdecl}
Expand All @@ -18011,7 +18011,7 @@
Equivalent to: \tcode{++*this;}
\end{itemdescr}

\indexlibrarymember{operator==}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{operator==}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
friend constexpr bool operator==(const @\exposid{iterator}@& x, const sentinel_t<@\exposid{Base}@>& y);
\end{itemdecl}
Expand All @@ -18022,7 +18022,7 @@
\tcode{x.\exposid{current_} == y}.
\end{itemdescr}

\indexlibrarymember{operator-}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{operator-}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
friend constexpr difference_type operator-(const sentinel_t<@\exposid{Base}@>& y, const @\exposid{iterator}@& x)
requires @\libconcept{sized_sentinel_for}@<sentinel_t<@\exposid{Base}@>, iterator_t<@\exposid{Base}@>>;
Expand All @@ -18034,7 +18034,7 @@
\tcode{y - x.\exposid{current_}}.
\end{itemdescr}

\indexlibrarymember{operator-}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{operator-}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
friend constexpr difference_type operator-(const @\exposid{iterator}@& x, const sentinel_t<@\exposid{Base}@>& y)
requires @\libconcept{sized_sentinel_for}@<sentinel_t<@\exposid{Base}@>, iterator_t<@\exposid{Base}@>>;
Expand All @@ -18046,7 +18046,7 @@
\tcode{x.\exposid{current_} - y}.
\end{itemdescr}

\indexlibrarymember{iter_move}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{iter_move}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
friend constexpr range_rvalue_reference_t<@\exposid{Base}@> iter_move(const @\exposid{iterator}@& i)
noexcept(noexcept(ranges::iter_move(i.@\exposid{current_}@)));
Expand All @@ -18058,7 +18058,7 @@
Equivalent to: \tcode{return ranges::iter_move(i.\exposid{current_});}
\end{itemdescr}

\indexlibrarymember{iter_swap}{to_input_view::\exposid{iterator}}%
\indexlibrarymember{iter_swap}{as_input_view::\exposid{iterator}}%
\begin{itemdecl}
friend constexpr void iter_swap(const @\exposid{iterator}@& x, const @\exposid{iterator}@& y)
noexcept(noexcept(ranges::iter_swap(x.@\exposid{current_}@, y.@\exposid{current_}@)))
Expand Down
2 changes: 1 addition & 1 deletion source/support.tex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -789,6 +789,7 @@
#define @\defnlibxname{cpp_lib_ranges}@ 202406L
// also in \libheader{algorithm}, \libheader{functional}, \libheader{iterator}, \libheader{memory}, \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_as_const}@ 202311L // freestanding, also in \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_as_input}@ 202502L // freestanding, also in \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_as_rvalue}@ 202207L // freestanding, also in \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_cache_latest}@ 202411L // freestanding, also in \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_cartesian_product}@ 202207L // freestanding, also in \libheader{ranges}
Expand All @@ -809,7 +810,6 @@
#define @\defnlibxname{cpp_lib_ranges_starts_ends_with}@ 202106L // freestanding, also in \libheader{algorithm}
#define @\defnlibxname{cpp_lib_ranges_stride}@ 202207L // freestanding, also in \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_to_container}@ 202202L // freestanding, also in \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_to_input}@ 202502L // freestanding, also in \libheader{ranges}
#define @\defnlibxname{cpp_lib_ranges_zip}@ 202110L
// freestanding, also in \libheader{ranges}, \libheader{tuple}, \libheader{utility}
#define @\defnlibxname{cpp_lib_ratio}@ 202306L // freestanding, also in \libheader{ratio}
Expand Down
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