operator-(std::counted_iterator<I>, std::default_sentinel_t)

Since C++20
  1. Returns the negative distance to the end.

# Declarations

friend constexpr std::iter_difference_t<I> operator-(
const counted_iterator& x, std::default_sentinel_t );

(since C++20)

friend constexpr std::iter_difference_t<I> operator-(
std::default_sentinel_t, const counted_iterator& y );

(since C++20)

# Parameters

# Example

#include <initializer_list>
#include <iterator>
 
int main()
{
    constexpr static auto v = {1, 2, 3, 4};
    constexpr std::counted_iterator<std::initializer_list<int>::iterator>
        it{v.begin(), 3};
    constexpr auto d1 = it - std::default_sentinel;
    static_assert(d1 == -3); // (1)
    constexpr auto d2 = std::default_sentinel - it;
    static_assert(d2 == +3); // (2)
}

# See also