NAME¶

std::default_sentinel_t,std::default_sentinel - std::default_sentinel_t,std::default_sentinel

Synopsis¶

Defined in header <iterator>
struct default_sentinel_t {}; (1) (since C++20)
inline constexpr default_sentinel_t default_sentinel{}; (2) (since C++20)

1) default_sentinel_t is an empty class type used to denote the end of a range. It
can be used together with iterator types that know the bound of their range (e.g.,
std::counted_iterator).
2) default_sentinel is a constant of type default_sentinel_t.

Example¶

// Run this code

#include <algorithm>
#include <iostream>
#include <iterator>
#include <list>

int main()
{
std::list<int> l{3, 1, 4, 1, 5, 9, 2, 6};

std::ranges::copy(std::counted_iterator(std::begin(l), 4),
std::default_sentinel, std::ostream_iterator<int>{std::cout, " "});
std::cout << '\n';
}

Output:¶

3 1 4 1

See also¶

istream_iterator input iterator that reads from std::basic_istream
(class template)
istreambuf_iterator input iterator that reads from std::basic_streambuf
(class template)
counted_iterator iterator adaptor that tracks the distance to the end of the
(C++20) range
(class template)