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std::iter_move(std::common_iterator)

From cppreference.com
 
 
Iterator library
Iterator concepts
Iterator primitives
Algorithm concepts and utilities
Indirect callable concepts
Common algorithm requirements
Utilities
(C++20)
Iterator adaptors
Stream iterators
Iterator customization points
Iterator operations
(C++11)
(C++11)
Range access
(C++11)(C++14)
(C++11)(C++14)
(C++17)(C++20)
(C++14)(C++14)
(C++14)(C++14)
(C++17)
(C++17)
 
 
friend std::iter_rvalue_reference_t<I>

  std::iter_move( const std::common_iterator& i )
    noexcept(noexcept(ranges::iter_move(std::declval<const I&>()))

      requires std::input_iterator<I>;
(since C++20)

Casts the result of dereferencing the underlying iterator to its associated rvalue reference type. The behavior is undefined if i.var does not hold an I object (i.e. an iterator).

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.

Contents

[edit] Parameters

i - a source iterator adaptor.

[edit] Return value

An rvalue reference or a prvalue temporary.

[edit] Complexity

Constant.

[edit] Example

#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++ == 0 ? "" : ", ") << quoted(s);
    std::cout << " }\n";
}
 
int main()
{
    std::vector<std::string> p { "Andromeda", "Cassiopeia", "Phoenix" }, q;
 
    print("p", p), print("q", q);
 
    using CI = std::common_iterator<
                   std::counted_iterator<std::vector<std::string>::iterator>,
                   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" }

[edit] See also

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