std::counted_iterator<I>::base

Since C++20

Returns the underlying base iterator.

# Declarations

constexpr const I& base() const& noexcept;

(since C++20)

constexpr I base() &&;

(since C++20)

# Example

#include <algorithm>
#include <iostream>
#include <iterator>
#include <type_traits>
#include <vector>
 
int main()
{
    std::vector<int> v{0, 1, 2, 3, 4};
 
    std::reverse_iterator<std::vector<int>::iterator> reverse{v.rbegin()};
 
    std::counted_iterator counted{reverse, 3};
 
    static_assert(std::is_same<
        decltype(counted.base()),
        std::reverse_iterator<std::vector<int>::iterator> const&
    >{});
 
    std::cout << "Print with reverse_iterator: ";
    for (auto r = counted.base(); r != v.rend(); ++r)
        std::cout << *r << ' ';
    std::cout << '\n';
 
    std::cout << "Print with counted_iterator: ";
    for (; counted != std::default_sentinel; ++counted)
        std::cout << counted[0] << ' ';
    std::cout << '\n';
}

# Defect reports

DR	Applied to	Behavior as published	Correct behavior
LWG 3391	C++20	the const version of base returns a copy of the underlying iterator	returns a reference
LWG 3593	C++20	the const version of base returns a reference but might not be noexcept	made noexcept

std::counted_iterator<I>::base

# Declarations

# Example

# Defect reports

# See also