std::iter_move(std::reverse_iterator)

 

C++

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Technical specifications

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Iterator library

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Algorithm concepts and utilities
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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)
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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
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ranges::iter_move (C++20)
ranges::iter_swap (C++20)
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advance distance prev (C++11) next (C++11)	ranges::advance (C++20) ranges::distance (C++20) ranges::prev (C++20) ranges::next (C++20)
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std::reverse_iterator

Member functions

reverse_iterator::reverse_iterator

reverse_iterator::operator=

reverse_iterator::base

reverse_iterator::operator*reverse_iterator::operator->

reverse_iterator::operator[]

reverse_iterator::operator++reverse_iterator::operator+reverse_iterator::operator+=reverse_iterator::operator--reverse_iterator::operator-reverse_iterator::operator-=

Non-member functions

operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20)

operator+

operator-

iter_move (C++20)

iter_swap (C++20)

make_reverse_iterator (C++14)

 

friend constexpr std::iter_rvalue_reference_t<Iter>     iter_move( const std::reverse_iterator& i ) noexcept(/* see below */);		(since C++20)

Casts the result of dereferencing the adjusted underlying iterator to its associated rvalue reference type.

The function body is equivalent to:

auto tmp = i.base();
return std::ranges::iter_move(--tmp);

This function template is not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::reverse_iterator<Iter> is an associated class of the arguments.

Parameters

i

-

a source reverse iterator.

Return value

An rvalue reference or a prvalue temporary.

Complexity

Constant.

Exceptions

noexcept specification:  

noexcept(

  std::is_nothrow_copy_constructible_v<Iter> &&
  noexcept(std::ranges::iter_move(--std::declval<Iter&>()))

)

Example

Run this code

#include <iomanip>
#include <iostream>
#include <iterator>
#include <string>
#include <vector>
 
void print(auto const& rem, auto const& v) {
    for (std::cout << rem << "[" << size(v) << "] { "; auto const& s : v)
        std::cout << quoted(s) << " ";
    std::cout << "}\n";
}
 
int main()
{
    std::vector<std::string> p { "Alpha", "Bravo", "Charlie" }, q;
 
    print("p", p), print("q", q);
 
    using RI = std::reverse_iterator<std::vector<std::string>::iterator>;
 
    for (RI iter{ p.rbegin() }, rend{ p.rend() }; iter != rend; ++iter) {
        q.emplace_back( /* ADL */ iter_move(iter) );
    }
 
    print("p", p), print("q", q);
}

Possible output:

p[3] { "Alpha" "Bravo" "Charlie" }
q[0] { }
p[3] { "" "" "" }
q[3] { "Charlie" "Bravo" "Alpha" }

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)