operator+,-(ranges::elements_view::iterator)

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< cpp‎ | ranges‎ | elements view‎ | iterator
 
 
Ranges library
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(C++23)
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(until C++23)(C++23)


 
 
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