iter_move(std::common_iterator)(3)

NAME
iter_move(std::common_iterator) - iter_move(std::common_iterator)

Synopsis
   friend constexpr decltype(auto) iter_move( const std::common_iterator&
   i )
                        (since
       noexcept(noexcept(ranges::iter_move(std::declval<const I&>())) C++20)
           requires std::input_iterator<I>;
   Casts the result of dereferencing the underlying iterator to its associated rvalue
   reference type.
   The function body is equivalent to: return
   std::ranges::iter_move(std::get<I>(i.var));.
   This function is not visible to ordinary unqualified or qualified lookup, and can
   only be found by argument-dependent lookup when std::common_iterator<I, S> is an
   associated class of the arguments.
   If i.var does not hold an I object (i.e. an iterator), the behavior is undefined.

Parameters
   i - a source iterator adaptor

Return value
   An rvalue reference or a prvalue temporary.

Complexity
   Constant.

Example
// Run this code
 #include <iomanip>
 #include <iostream>
 #include <iterator>
 #include <string>
 #include <vector>
 void print(auto const& rem, auto const& v)
 {
     std::cout << rem << '[' << size(v) << "] { ";
     for (int o{}; auto const& s : v)
         std::cout << (o++ ? ", " : "") << std::quoted(s);
     std::cout << " }\n";
 }
 int main()
 {
     std::vector<std::string> p{"Andromeda", "Cassiopeia", "Phoenix"}, q;
     print("p", p);
     print("q", q);
     using CTI = std::counted_iterator<std::vector<std::string>::iterator>;
     using CI = std::common_iterator<CTI, std::default_sentinel_t>;
     CI last{std::default_sentinel};
     for (CI first{{p.begin(), 2}}; first != last; ++first)
         q.emplace_back(/* ADL */ iter_move(first));
     print("p", p);
     print("q", q);
 }

Possible output:
 p[3] { "Andromeda", "Cassiopeia", "Phoenix" }
 q[0] { }
 p[3] { "", "", "Phoenix" }
 q[2] { "Andromeda", "Cassiopeia" }
   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 3953 C++20 the return type was changed to
                       std::iter_rvalue_reference_t<I> decltype(auto)

See also
   iter_move casts the result of dereferencing an object to its associated
   (C++20) rvalue reference type
                        (customization point object)
   iter_move casts the result of dereferencing the underlying iterator to
   (C++20) its associated rvalue reference type
                        (function)
   move obtains an rvalue reference
   (C++11) (function template)
   move_if_noexcept obtains an rvalue reference if the move constructor does not
   (C++11) throw
                        (function template)
   forward forwards a function argument
   (C++11) (function template)
   ranges::move moves a range of elements to a new location
   (C++20) (niebloid)
   ranges::move_backward moves a range of elements to a new location in backwards order
   (C++20) (niebloid)