NAME¶

std::ranges::views::as_rvalue,std::ranges::as_rvalue_view - std::ranges::views::as_rvalue,std::ranges::as_rvalue_view

Synopsis¶

Defined in header <ranges>
template< ranges::view V >

requires ranges::input_range<V> (1) (since C++23)
class as_rvalue_view

: public ranges::view_interface<as_rvalue_view<V>>
namespace views {

inline constexpr /* unspecified */ as_rvalue = /* unspecified (2) (since C++23)
*/;

}
Call signature
template< ranges::viewable_range R >

requires /* see below */ (since C++23)

constexpr ranges::view auto as_rvalue( R&& r );

1) A range adaptor that represents a view of underlying view whose elements are
rvalues.
2) RangeAdaptorObject. Let e be a subexpression and let T be decltype((e)). Then the
expression views::as_rvalue(e) is expression-equivalent to:
* views::all(e), if it is a well-formed expression and
std::same_as<ranges::range_rvalue_reference_t<T>, ranges::range_reference_t<T>>
is true;
* as_rvalue_view{e} otherwise.

Member functions¶

constructor constructs an as_rvalue_view
(public member function)
base returns the underlying view V
(public member function)
begin returns the beginning iterator of the as_rvalue_view
(public member function)
end returns the end iterator of the as_rvalue_view
(public member function)
size returns the size of the view if it is bounded
(public member function)
Inherited from std::ranges::view_interface
empty returns whether the derived view is empty. Provided if it satisfies
(C++20) sized_range or forward_range.
(public member function of std::ranges::view_interface<D>)
cbegin returns a constant iterator to the beginning of the range.
(C++23) (public member function of std::ranges::view_interface<D>)
cend returns a sentinel for the constant iterator of the range.
(C++23) (public member function of std::ranges::view_interface<D>)
operator bool returns whether the derived view is not empty. Provided if
(C++20) ranges::empty is applicable to it.
(public member function of std::ranges::view_interface<D>)
front returns the first element in the derived view. Provided if it
(C++20) satisfies forward_range.
(public member function of std::ranges::view_interface<D>)
back returns the last element in the derived view. Provided if it satisfies
(C++20) bidirectional_range and common_range.
(public member function of std::ranges::view_interface<D>)
operator[] returns the n^th element in the derived view. Provided if it satisfies
(C++20) random_access_range.
(public member function of std::ranges::view_interface<D>)

std::ranges::as_rvalue_view::as_rvalue_view

as_rvalue_view() requires std::default_initializable<V> = default; (1) (since C++23)
constexpr explicit as_rvalue_view( V base ); (2) (since C++23)

1) Value-initializes base_ via its default member initializer (= V()).
2) Initializes base_ with std::move(base).

Parameters¶

base - a view

std::ranges::as_rvalue_view::base

constexpr V base() const& requires std::copy_constructible<V>; (1) (since C++23)
constexpr V base() &&; (2) (since C++23)

Returns the underlying view.

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::as_rvalue_view::begin

constexpr auto begin() requires (!__simple_view<V>); (1) (since C++23)
constexpr auto begin() const requires ranges::range<const V>; (2) (since C++23)

1,2) Returns std::move_iterator(ranges::begin(base_)).

std::ranges::as_rvalue_view::end

constexpr auto end() requires (!__simple_view<V>); (1) (since C++23)
constexpr auto end() const requires ranges::range<const V>; (2) (since C++23)

1) Returns std::move_iterator(ranges::end(base_)) if V models common_range,
otherwise std::move_sentinel(ranges::end(base_)).
2) Returns std::move_iterator(ranges::end(base_)) if const V models common_range,
otherwise std::move_sentinel(ranges::end(base_)).

std::ranges::as_rvalue_view::size

constexpr auto size() requires ranges::sized_range<V>; (1) (since C++23)
constexpr auto size() const requires ranges::sized_range<const V>; (2) (since C++23)

Returns the size of the view if the view is bounded.

1,2) Equivalent to return ranges::size(base_);

Deduction guides

template< class R > (since C++23)
as_rvalue_view( R&& ) -> as_rvalue_view<views::all_t<R>>;

Helper templates

template< class T >

inline constexpr bool enable_borrowed_range<std::ranges::as_rvalue_view<T>> (since
= C++23)

std::ranges::enable_borrowed_range<T>;

This specialization of std::ranges::enable_borrowed_range makes as_rvalue_view
satisfy borrowed_range when the underlying view satisfies it.

Notes¶

Feature-test macro Value Std Feature
__cpp_lib_ranges_as_rvalue 202207L (C++23) std::ranges::as_rvalue_view

Example¶

This section is incomplete
Reason: example

See also¶

move_iterator iterator adaptor which dereferences to an rvalue
(C++11) (class template)
move_sentinel sentinel adaptor for use with std::move_iterator
(C++20) (class template)
ranges::as_const_view converts a view into a constant_range
views::as_const (class template) (range adaptor object)
(C++23)

Category:¶

* Todo with reason