std::reverse_iterator::base - cppreference.com (original) (raw)
| iterator_type base() const; | | (constexpr since C++17) | | ---------------------------- | | ----------------------- |
Returns the underlying iterator.
[edit] Return value
[current](../reverse%5Fiterator.html#current "cpp/iterator/reverse iterator")
[edit] Notes
The base iterator refers to the element that is next (from the iterator_type perspective) to the element the reverse_iterator is currently pointing to. That is &*(this->base() - 1) == &*(*this).
[edit] Example
#include #include #include int main() { std::vector v = {0, 1, 2, 3, 4, 5}; using RevIt = std::reverse_iterator<std::vector::iterator>; const auto it = v.begin() + 3; RevIt r_it{it}; std::cout << "*it == " << *it << '\n' << "*r_it == " << *r_it << '\n' << "*r_it.base() == " << r_it.base() << '\n' << "(r_it.base() - 1) == " << *(r_it.base() - 1) << '\n'; RevIt r_end{v.begin()}; RevIt r_begin{v.end()}; for (auto it = r_end.base(); it != r_begin.base(); ++it) std::cout << *it << ' '; std::cout << '\n'; for (auto it = r_begin; it != r_end; ++it) std::cout << *it << ' '; std::cout << '\n'; }
Output:
*it == 3 *r_it == 2 *r_it.base() == 3 *(r_it.base() - 1) == 2 0 1 2 3 4 5 5 4 3 2 1 0