iter_move(std::common_iterator)

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Iterator library

Iterator concepts
indirectly_readable (C++20) indirectly_writable (C++20) weakly_incrementable (C++20) incrementable (C++20) input_or_output_iterator (C++20) sentinel_for (C++20) sized_sentinel_for (C++20)	input_iterator (C++20) output_iterator (C++20) forward_iterator (C++20) bidirectional_iterator (C++20) random_access_iterator (C++20) contiguous_iterator (C++20)
Iterator primitives
iterator_traits input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag (C++20) iterator (deprecated in C++17)	incrementable_traits (C++20) indirectly_readable_traits (C++20) iter_value_titer_difference_titer_reference_titer_const_reference_titer_rvalue_reference_titer_common_reference_t (C++20)(C++20)(C++20)(C++23)(C++20)(C++20)
Algorithm concepts and utilities
Indirect callable concepts
indirectly_unary_invocableindirectly_regular_unary_invocable (C++20)(C++20)   indirect_unary_predicate (C++20)	indirect_binary_predicate (C++20) indirect_equivalence_relation (C++20) indirect_strict_weak_order (C++20)
Common algorithm requirements
indirectly_movable (C++20) indirectly_movable_storable (C++20) indirectly_copyable (C++20) indirectly_copyable_storable (C++20)	indirectly_swappable (C++20) indirectly_comparable (C++20) permutable (C++20) mergeable (C++20) sortable (C++20)
Utilities
indirect_result_t (C++20)	projected (C++20)
Iterator adaptors
reverse_iterator move_iterator (C++11) move_sentinel (C++20) common_iterator (C++20) counted_iterator (C++20) basic_const_iterator (C++23) const_iterator (C++23) const_sentinel (C++23) back_insert_iterator front_insert_iterator insert_iterator	make_reverse_iterator (C++14) make_move_iterator (C++11) default_sentinel_tdefault_sentinel (C++20)(C++20) unreachable_sentinel_tunreachable_sentinel (C++20)(C++20) make_const_iterator (C++23) make_const_sentinel (C++23) back_inserter front_inserter inserter
Stream iterators
istream_iterator ostream_iterator	istreambuf_iterator ostreambuf_iterator
Iterator customization points
ranges::iter_move (C++20)
ranges::iter_swap (C++20)
Iterator operations
advance distance prev (C++11) next (C++11)	ranges::advance (C++20) ranges::distance (C++20) ranges::prev (C++20) ranges::next (C++20)
Range access
begincbegin (C++11)(C++14) endcend (C++11)(C++14) sizessize (C++17)(C++20)	rbegincrbegin (C++14)(C++14) rendcrend (C++14)(C++14) empty (C++17) data (C++17)

 

std::common_iterator

Member functions

common_iterator::common_iterator (C++20)

common_iterator::operator= (C++20)

common_iterator::operator*common_iterator::operator-> (C++20)(C++20)

common_iterator::operator++common_iterator::operator++(int) (C++20)(C++20)

Non-member functions

operator== (C++20)

operator- (C++20)

iter_move (C++20)

iter_swap (C++20)

Helper classes

incrementable_traits (C++20)

iterator_traits (C++20)

 

friend std::iter_rvalue_reference_t<I>   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.

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++ == 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" }

See also

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