operator+,-(ranges::enumerate_view::iterator)
friend constexpr /* iterator */
operator+( const /* iterator */& i, difference_type n )
requires ranges::random_access_range</* Base */>;
| (1) | (since C++23) |
friend constexpr /* iterator */
operator+( difference_type n, const /* iterator */& i )
requires ranges::random_access_range</* Base */>;
| (2) | (since C++23) |
friend constexpr /* iterator */
operator-( const /* iterator */& i, difference_type n )
requires ranges::random_access_range</* Base */>;
| (3) | (since C++23) |
friend constexpr difference_type
operator-( const /* iterator */& i, const /* iterator */& j ) noexcept;
| (4) | (since C++23) |
Performs iterator arithmetic or calculates the distance.
pos_ is the underlying index, and Base is the (possibly const-qualified) type of underlying view.
Equivalent to:
1)
auto temp = i; temp += n; return temp;
2)
return i + n;
3)
auto temp = i; temp -= n; return temp;
4)
return i.pos_ - j.pos_;
These functions are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when enumerate_view::iterator<Const> is an associated class of the arguments.
Parameters
| i, j | - | the iterators |
| n | - | position relative to current location |
Return value
1,2) An incremented iterator.
3) A decremented iterator.
4) A distance between given iterators.
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 3912 | C++23 | overload (4) was not noexcept | it is noexcept |
See also
| advances or decrements the underlying iterator (public member function) |
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