std::ranges::adjacent_view<V,N>::iterator<Const>::operator++,--,+=,-=
From cppreference.com
constexpr /*iterator*/& operator++();
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(1) | (since C++23) |
constexpr /*iterator*/ operator++( int );
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(2) | (since C++23) |
constexpr /*iterator*/& operator--()
requires ranges::bidirectional_range<Base>;
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(3) | (since C++23) |
constexpr /*iterator*/ operator--( int )
requires ranges::bidirectional_range<Base>;
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(4) | (since C++23) |
constexpr /*iterator*/& operator+=( difference_type n )
requires ranges::random_access_range<Base>;
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(5) | (since C++23) |
constexpr /*iterator*/& operator-=( difference_type n )
requires ranges::random_access_range<Base>;
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(6) | (since C++23) |
Increments or decrements the iterator.
Let current_ be an underlying array of iterators.
1) Equivalent to:
The behavior is undefined if before the call the
for (auto& i : current_)
i = std::ranges::next(i);
return *this;
current_.back() is not incrementable.2) Equivalent to:
auto tmp = *this;
++*this;
return tmp;
3) Equivalent to:
The behavior is undefined if before the call the
for (auto& i : current_)
i = std::ranges::prev(i);
return *this;
current_.front() is not decrementable.4) Equivalent to:
auto tmp = *this;
--*this;
return tmp;
5) Equivalent to:
The behavior is undefined if before the call the
for (auto& i : current_)
i = i + n;
return *this;
current_.back() + n does not have well-defined behavior.6) Equivalent to:
The behavior is undefined if before the call the
for (auto& i : current_)
i = i - n;
return *this;
current_.front() - n does not have well-defined behavior.Parameters
| n | - | position relative to current location |
Return value
1,3,5,6)
*this2,4) A copy of
*this that was made before the change.Example
Run this code
#include <cassert>
#include <list>
#include <ranges>
#include <utility>
#include <vector>
int main()
{
{
auto v = std::vector{0, 1, 2, 3, 4, 5};
auto i = (v | std::views::pairwise).begin();
assert((*i == std::pair{0, 1}));
++i; // overload (1)
assert((*i == std::pair{1, 2}));
--i; // overload (3)
assert((*i == std::pair{0, 1}));
i += 2; // overload (5)
assert((*i == std::pair{2, 3}));
i -= 2; // overload (6)
assert((*i == std::pair{0, 1}));
}
{
auto v = std::list{0, 1, 2, 3, 4, 5};
auto i = (v | std::views::pairwise).begin();
assert((*i == std::pair{0, 1}));
++i; // overload (1)
assert((*i == std::pair{1, 2}));
--i; // overload (3)
assert((*i == std::pair{0, 1}));
// i += 2; // Error: v is not a random_access_range; overload (5)
// i -= 2; // Error: v is not a random_access_range; overload (6)
}
}
See also
(C++23) |
performs iterator arithmetic (public member function) |