std::ranges:: views:: to_input, std::ranges:: to_input_view

Defined in header <ranges>
template < ranges:: input_range V > requires ranges:: view < V > class to_input_view : public ranges:: view_interface < to_input_view < V >>	(1)	(since C++26)
namespace views { inline constexpr /* unspecified */ to_input = /* unspecified */ ; }	(2)	(since C++26)
Call signature
template < ranges:: viewable_range R > requires /* see below */ constexpr ranges:: view auto to_input ( R && r ) ;		(since C++26)

Consequently, to_input_view never models range concepts that are stronger than input_range . In particular, it does not model all of these:

• forward_range
• bidirectional_range
• random_access_range
• contiguous_range

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 1 Data members 2 Member functions 2.1 Inherited from std::ranges::view_interface 3 std::ranges::to_input_view:: to_input_view 3.1 Parameters 4 std::ranges::to_input_view:: base 5 std::ranges::to_input_view:: begin 6 std::ranges::to_input_view:: end 7 std::ranges::to_input_view:: size 7.1 Deduction guides 7.2 Nested classes 7.3 Helper templates 7.4 Notes 7.5 Example 7.6 See also

Data members

Member	Description
V base_ (private)	the underlying view ( exposition-only member object* )

Member functions

(constructor)	constructs a to_input_view (public member function)
base	returns a copy of the underlying (adapted) view (public member function)
begin	returns an iterator to the beginning (public member function)
end	returns an iterator or a sentinel to the end (public member function)
size	returns the number of elements. Provided only if the underlying (adapted) range satisfies sized_range . (public member function)
Inherited from std::ranges::view_interface
empty	returns whether the derived view is empty, provided only if it satisfies sized_range or forward_range (public member function of std::ranges::view_interface<D> )
cbegin (C++23)	returns a constant iterator to the beginning of the range (public member function of std::ranges::view_interface<D> )
cend (C++23)	returns a sentinel for the constant iterator of the range (public member function of std::ranges::view_interface<D> )
operator bool	returns whether the derived view is not empty, provided only if ranges::empty is applicable to it (public member function of std::ranges::view_interface<D> )
data	gets the address of derived view's data, provided only if its iterator type satisfies contiguous_iterator (public member function of std::ranges::view_interface<D> )
front	returns the first element in the derived view, provided if it satisfies forward_range (public member function of std::ranges::view_interface<D> )
back	returns the last element in the derived view, provided only if it satisfies 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 only if it satisfies random_access_range (public member function of std::ranges::view_interface<D> )

Deduction guides

template < class R > to_input_view ( R && ) - > to_input_view < views:: all_t < R >> ;		(since C++26)

Nested classes

iterator

the iterator type ( exposition-only member class template* )

Helper templates

template < class T > constexpr bool enable_borrowed_range < std :: ranges :: to_input_view < T >> = ranges:: enable_borrowed_range < T > ;		(since C++26)

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

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

Example

This section is incomplete Reason: no example

See also

ranges::input_range (C++20)	specifies a range whose iterator type satisfies input_iterator (concept)
ranges::common_view views::common (C++20)	converts a view into a common_range (class template) (range adaptor object)