operator+,-(ranges::elements_view::iterator)
friend constexpr /*iterator*/ operator+( const /*iterator*/& i, difference_type n )
requires ranges::random_access_range<Base>;
| (1) | (since C++20) |
friend constexpr /*iterator*/ operator+( difference_type n, const /*iterator*/& i )
requires ranges::random_access_range<Base>;
| (2) | (since C++20) |
friend constexpr /*iterator*/ operator-( const /*iterator*/& i, difference_type n )
requires ranges::random_access_range<Base>;
| (3) | (since C++20) |
friend constexpr difference_type operator-( const /*iterator*/& x,
const /*iterator*/& y )
requires std::sized_sentinel_for<ranges::iterator_t<Base>, ranges::iterator_t<Base>>;
| (4) | (since C++20) |
1,2) Returns the iterator
i incremented by n.
3) Returns the iterator
i decremented by n.
4) Returns the distance between
x and y.These functions are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when elements_view::iterator<Const> is an associated class of the arguments.
Parameters
| i, x, y | - | the iterators |
| n | - | position relative to current location |
Return value
1,2)
[&]{ auto j = i; j += n; return j; }()
3)
[&]{ auto j = i; j -= n; return j; }()
4)
x.base() - y.base()
Example
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3483 | C++20 |
elements_view::iterator's difference is overconstrained | requirement is relaxed |
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