Difference between revisions of "cpp/ranges/split view"

Revision as of 13:53, 26 April 2023

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.

Data members

Typical implementations of split_view hold three non-static data members:

• the underlying view of type V (shown here as base_ for exposition only), and
• the pattern (shown here as pattern_ for exposition only) that is used as a delimiter to split the underlying view.
• an object equivalent to std::optional<ranges::subrange<ranges::iterator_t<V>>> (shown here as cached_begin_ for exposition only) that caches the result of a first call to begin().

Member functions

Nested classes

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.

Example

#include <iomanip>
#include <iostream>
#include <ranges>
#include <string_view>
 
int main()
{
    constexpr std::string_view words{"Hello^_^C++^_^20^_^!"};
    constexpr std::string_view delim{"^_^"};
 
    for (const auto word : std::views::split(words, delim))
        std::cout << std::quoted(std::string_view{word.begin(), word.end()}) << ' ';
}

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

Defect reports

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

See also