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std::move_iterator<Iter>::operator*,->

From cppreference.com
 
 
Iterator library
Iterator concepts
Iterator primitives
Algorithm concepts and utilities
Indirect callable concepts
Common algorithm requirements
(C++20)
(C++20)
(C++20)
Utilities
(C++20)
Iterator adaptors
Range access
(C++11)(C++14)
(C++14)(C++14)  
(C++11)(C++14)
(C++14)(C++14)  
(C++17)(C++20)
(C++17)
(C++17)
 
 
reference operator*() const;
(1) (since C++11)
(constexpr since C++17)
pointer operator->() const;
(2) (since C++11)
(constexpr since C++17)
(deprecated in C++20)

Returns an rvalue reference or pointer to the current element.

Contents

[edit] Return value

1) static_cast<reference>(*current )(until C++20)ranges::iter_move(current )(since C++20)

[edit] Notes

operator-> is deprecated because deferencing its result may yield an lvalue. This may lead to unintended behavior.

[edit] Example

#include <iomanip>
#include <iostream>
#include <iterator>
#include <string>
#include <vector>
 
void print(auto rem, const auto& v)
{
    for (std::cout << rem; const auto& e : v)
        std::cout << std::quoted(e) << ' ';
    std::cout << '\n';
}
 
int main()
{
    std::vector<std::string> p{"alpha", "beta", "gamma", "delta"}, q;
    print("1) p: ", p);
    for (std::move_iterator it{p.begin()}, end{p.end()}; it != end; ++it)
    {
        it->push_back('!'); // calls -> string::push_back(char)
        q.emplace_back(*it); // *it <- overload (1)
    }
    print("2) p: ", p);
    print("3) q: ", q);
 
    std::vector v{1, 2, 3};
    std::move_iterator it{v.begin()};
    // *it = 13; // error: using rvalue as lvalue
}

Possible output:

1) p: "alpha" "beta" "gamma" "delta"
2) p: "" "" "" ""
3) q: "alpha!" "beta!" "gamma!" "delta!"

[edit] 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 2106 C++11 operator* would return a dangling
reference if *current yields a prvalue
returns the object
in this case

[edit] See also

accesses an element by index
(public member function) [edit]