std::ranges::views::split, std::ranges::split_view
<ranges>
requires ranges::view <V> &&
ranges::view <Pattern> &&
std::indirectly_comparable <ranges::iterator_t <V>,
ranges::iterator_t <Pattern>,
ranges::equal_to >
class split_view
inline constexpr /* unspecified */ split = /* unspecified */;
requires /* see below */
constexpr /* range adaptor closure */ split( Pattern&& pattern );
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.
Unlike lazy_split_view
, split_view
maintains the continuity of the subrange, making it suitable for string splitting.
Contents
[edit] Data members
Pattern
pattern_
(private)
the pattern object that is used as a delimiter to split the underlying view
(exposition-only member object*)
<ranges::iterator_t <V>>> cached_begin_
(private)
an object that caches the result of the first call to begin()
(exposition-only member object*)
[edit] Member functions
Inherited from std::ranges::view_interface
sized_range
or forward_range
(public member function of
std::ranges::view_interface<D>
) [edit]
(public member function of
std::ranges::view_interface<D>
) [edit]
(public member function of
std::ranges::view_interface<D>
) [edit]
(public member function of
std::ranges::view_interface<D>
) [edit]
forward_range
(public member function of
std::ranges::view_interface<D>
) [edit]
[edit] Nested classes
[edit] Deduction guides
[edit] 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.
[edit] Example
#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" "!"
[edit] 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 used
|
it is redesigned |
[edit] See also
view
over the subranges obtained from splitting another view
using a delimiter(class template) (range adaptor object)[edit]