std::common_iterator<I,S>:: operator=

Assigns the underlying std::variant member object var from that of x .

Let i is x. var . index ( ) . Then, this assignment is equivalent to:

• std :: get < i > ( var ) = std :: get < i > ( x. var ) , if var. index ( ) == i ,
• var. emplace < i > ( std :: get < i > ( x. var ) ) otherwise.

The behavior is undefined if x is in an invalid state, that is, x. var . valueless_by_exception ( ) is equal to true .

Parameters

Return value

* this

Example

#include <algorithm>
#include <initializer_list>
#include <iostream>
#include <iterator>
 
int main()
{
    const auto il = {1, 2, 3, 4, 5, 6};
    using CI = std::common_iterator<
                   std::counted_iterator<std::initializer_list<int>::iterator>,
                   std::default_sentinel_t>;
    CI first{std::counted_iterator{std::next(begin(il), 1), ssize(il) - 1}};
    const CI first2{std::counted_iterator{std::next(begin(il), 2), ssize(il) - 2}};
    const CI last{std::default_sentinel};
    std::copy(first, last, std::ostream_iterator<int>{std::cout, " "});
    std::cout << '\n';
    first = first2;
    std::copy(first, last, std::ostream_iterator<int>{std::cout, " "});
    std::cout << '\n';
}

2 3 4 5 6 
3 4 5 6

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also