NAME¶

std::ranges::views::split,std::ranges::split_view - std::ranges::views::split,std::ranges::split_view

Synopsis¶

Defined in header <ranges>
template< ranges::forward_range V, ranges::forward_range Pattern >

requires ranges::view<V> &&
ranges::view<Pattern> &&
std::indirectly_comparable<ranges::iterator_t<V>, (1) (since C++20)
ranges::iterator_t<Pattern>,
ranges::equal_to>
class split_view

: public ranges::view_interface<split_view<V, Pattern>>
namespace views {

inline constexpr /* unspecified */ split = /* unspecified */; (2) (since C++20)

}
Call signature
template< ranges::viewable_range R, class Pattern >

requires /* see below */ (since C++20)

constexpr ranges::view auto split( R&& r, Pattern&& pattern );
template< class Pattern > (since C++20)
constexpr /* range adaptor closure */ split( Pattern&& pattern );

1) split_view takes a view and a delimiter, and splits the view into subranges on
the delimiter.
2) RangeAdaptorObject. The expression views::split(e, p) is expression-equivalent to
split_view(e, p) for any suitable subexpressions e and p.

split_view models the concepts forward_range, and common_range when the underlying
view V models respective concepts.

The inner range (ranges::range_reference_t<split_view>) is a
ranges::subrange<ranges::iterator_t<V>>, which models common_range, models
sized_range when ranges::iterator_t<V> models
std::sized_sentinel_for<ranges::iterator_t<V>>, and models contiguous_range,
random_access_range, bidirectional_range, and forward_range when V models respective
concepts.

Member functions¶

constructor constructs a split_view
(C++20) (public member function)
base returns a copy of the underlying (adapted) view
(C++20) (public member function)
begin returns an iterator to the beginning
(C++20) (public member function)
end returns an iterator or a sentinel to the end
(C++20) (public member function)
find_next searches for the next occurrence of the pattern
(C++20) (exposition-only 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>)

Nested classes

iterator the iterator type
(C++20) (exposition-only member class*)
sentinel the sentinel type
(C++20) (exposition-only member class*)

Deduction guides

Notes¶

Before P2210R2, split_view used a lazy mechanism for splitting, and thus could not
keep the bidirectional, random access, or contiguous properties of the underlying
view, or make the iterator type of the inner range same as that of the underlying
view. Consequently, it is redesigned by P2210R2, and the lazy mechanism is moved to
lazy_split_view.

The delimiter pattern generally should not be an ordinary string literal, as it will
consider the null terminator to be necessary part of the delimiter; therefore, it is
advisable to use a std::string_view literal instead.

Example¶

// Run this code

#include <iomanip>
#include <iostream>
#include <ranges>
#include <string_view>

int main()
{
using std::operator""sv;
constexpr auto words{"Hello^_^C++^_^20^_^!"sv};
constexpr auto delim{"^_^"sv};

for (const auto word : std::views::split(words, delim))
// with string_view's C++23 range constructor:
std::cout << std::quoted(std::string_view(word)) << ' ';
std::cout << '\n';
}

Output:¶

"Hello" "C++" "20" "!"

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
P2210R2 C++20 the old split_view was too lazy to be easily it is redesigned
used

See also¶

ranges::lazy_split_view a view over the subranges obtained from splitting another
views::lazy_split view using a delimiter
(C++20) (class template) (range adaptor object)
ranges::join_view a view consisting of the sequence obtained from flattening a
views::join view of ranges
(C++20) (class template) (range adaptor object)