< cpp‎ | ranges‎ | stride view‎ | iterator
Ranges library
Range access
Range conversions

Range primitives

Dangling iterator handling
Range concepts

Range factories
Range adaptors
Range generators
Range adaptor objects
Range adaptor closure objects
Helper items
(until C++23)(C++23)

constexpr /*iterator*/& operator++();
(1) (since C++23)
constexpr void operator++( int );
(2) (since C++23)
constexpr /*iterator*/ operator++( int )
  requires ranges::forward_range<Base>;
(3) (since C++23)
constexpr /*iterator*/& operator--()
  requires ranges::bidirectional_range<Base>;
(4) (since C++23)
constexpr /*iterator*/ operator--( int )
  requires ranges::bidirectional_range<Base>;
(5) (since C++23)
constexpr /*iterator*/& operator+=( difference_type n )
  requires ranges::random_access_range<Base>;
(6) (since C++23)
constexpr /*iterator*/& operator-=( difference_type n )
  requires ranges::random_access_range<Base>;
(7) (since C++23)

Increments or decrements the iterator.

Let current_, end_, stride_, and missing_ be the data members of the iterator.

1) Equivalent to
missing_ = ranges::advance(current_, stride_, end_);
return *this
Before the call current_ should not be equal to end_.
2) Equivalent to ++*this;.
3) Equivalent to auto tmp = *this; ++*this; return tmp;.
4) Equivalent to
ranges::advance(current_, missing_ - stride_);
missing_ = 0;
return *this;
5) Equivalent to auto tmp = *this; --*this; return tmp;.
6) Equivalent to
if (n > 0)
    ranges::advance(current_, stride_ * (n - 1));
    missing_ = ranges::advance(current_, stride_, end_);
else if (n < 0)
    ranges::advance(current_, stride_ * n + missing_);
    missing_ = 0;
return *this;

If n > 0, then before the call to this function the ranges::distance(current_, end_) must be greater than stride_ * (n - 1).

Note that if n < 0, the ranges::distance(current_, end_) is always greater than (non-positive) stride_ * (n - 1).
7) Equivalent to return *this += -n;


[edit] Parameters

n - position relative to current location

[edit] Return value

1,4,6,7) *this
2) (none)
3,5) a copy of *this that was made before the change

[edit] Example

[edit] See also

performs iterator arithmetic