std::ranges::views::to_input, std::ranges::to_input_view
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Concepts library (C++20)
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Execution control library (C++26)
Ranges library
(exposition-only member object*)
returns a constant iterator to the beginning of the range
(public member function of
returns a sentinel for the constant iterator of the range
(public member function of
(C++23)(C++23)
(C++23)(C++23)
(C++23)(C++23)
to_input_viewviews::to_input
(C++26)(C++26)
(C++23)(C++23)
(C++23)(C++23)
(C++23)(C++23)
(C++23)(C++23)
(C++23)(C++23)
(C++23)
(C++23)(C++23)
(C++23)
(C++23)(C++23)
(C++23)(C++23)
(C++23)(C++23)
(C++23)(C++23)
(C++23)(C++23)
(C++23)
std::ranges::to_input_view
Defined in header
<ranges>
template< ranges::input_range V >
(1)
(since C++26)
requires ranges::view <V>
class to_input_view
namespace views {
(2)
(since C++26)
inline constexpr /* unspecified */ to_input = /* unspecified */;
Call signature
template< ranges::viewable_range R >
(since C++26)
requires /* see below */
1) A range adaptor that represents a view of an underlying
view as an input_range-only and not a common_range.2) RangeAdaptorObject. Let e be a subexpression, and let T be decltype(e). Then the expression views::to_input(e) is expression-equivalent to:
- views::all (e), if it is a well-formed expression and all of the conditions below are true:
-
Tmodelsinput_range, -
Tdoes not satisfycommon_range, and -
Tdoes not satisfyforward_range.
-
- to_input_view{e} otherwise.
Consequently, to_input_view never models range concepts that are stronger than input_range. In particular, it does not model all of these:
Additionally, to_input_view does not model common_range. However, it does model borrowed_range, constant_range, and sized_range when the underlying view V models respective concepts.
Contents
[edit] Data members
Member
Description
V base_ (private)
the underlying view(exposition-only member object*)
[edit] Member functions
returns the number of elements. Provided only if the underlying (adapted) range satisfies
(public member function)
sized_range. (public member function)
Inherited from std::ranges::view_interface
returns whether the derived view is empty, provided only if it satisfies
(public member function of
sized_range or forward_range (public member function of
std::ranges::view_interface<D>) [edit]
(C++23)
(public member function of
std::ranges::view_interface<D>) [edit]
(C++23)
(public member function of
std::ranges::view_interface<D>) [edit]
returns whether the derived view is not empty, provided only if ranges::empty is applicable to it
(public member function of
(public member function of
std::ranges::view_interface<D>) [edit]
gets the address of derived view's data, provided only if its iterator type satisfies
(public member function of
contiguous_iterator (public member function of
std::ranges::view_interface<D>) [edit]
returns the first element in the derived view, provided if it satisfies
(public member function of
forward_range (public member function of
std::ranges::view_interface<D>) [edit]
returns the last element in the derived view, provided only if it satisfies
(public member function of
bidirectional_range and common_range (public member function of
std::ranges::view_interface<D>) [edit]
returns the
(public member function of
nth element in the derived view, provided only if it satisfies random_access_range (public member function of
std::ranges::view_interface<D>) [edit]
std::ranges::to_input_view::to_input_view
to_input_view() requires std::default_initializable <V> = default;
(1)
(since C++26)
constexpr explicit to_input_view( V base );
(2)
(since C++26)
1) Value-initializes
base_ via its default member initializer (= V()).2) Initializes
base_ with std::move(base).Parameters
base
-
a view
std::ranges::to_input_view::base
constexpr V base() const& requires std::copy_constructible <V>;
(1)
(since C++26)
constexpr V base() &&;
(2)
(since C++26)
1) Copy-constructs the result from the underlying view. Equivalent to return base_;.
2) Move-constructs the result from the underlying view. Equivalent to return std::move(base_);.
std::ranges::to_input_view::begin
constexpr auto begin() requires (!__simple_view<V>);
(1)
(since C++26)
constexpr auto begin() const requires ranges::range <const V>;
(2)
(since C++26)
1) Equivalent to return /*iterator*/<false>(ranges::begin (base_));
2) Equivalent to return /*iterator*/<true>(ranges::begin (base_));
std::ranges::to_input_view::end
constexpr auto end() requires (!__simple_view<V>);
(1)
(since C++26)
constexpr auto end() const requires ranges::range <const V>;
(2)
(since C++26)
1,2) Equivalent to return ranges::end (base_);
std::ranges::to_input_view::size
constexpr auto size() requires ranges::sized_range <V>;
(1)
(since C++26)
constexpr auto size() const requires ranges::sized_range <const V>;
(2)
(since C++26)
1,2) Equivalent to return ranges::size (base_);
[edit] Deduction guides
template< class R >
to_input_view( R&& ) -> to_input_view<views::all_t <R>>;
(since C++26)
to_input_view( R&& ) -> to_input_view<views::all_t <R>>;
[edit] Nested classes
[edit] Helper templates
template< class T >
(since C++26)
constexpr bool enable_borrowed_range<std::ranges::to_input_view<T>> =
This specialization of std::ranges::enable_borrowed_range makes to_input_view satisfy borrowed_range when the underlying view satisfies it.
[edit] Notes
to_input_view can be useful to avoid the overhead necessary to provide support for the operations needed for greater iterator strength.
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_ranges_to_input |
202502L |
(C++26) | std::ranges::to_input_view
|
[edit] Example
This section is incomplete
Reason: no example
Reason: no example