std::iter_move(std::reverse_iterator)

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std::reverse_iterator
 
friend constexpr std::iter_rvalue_reference_t<Iter>
    iter_move( const std::reverse_iterator& i ) noexcept(/* see below */);
 (since 哋它亢++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)
{
    std::cout << rem << '[' << size(v) << "] {";
    for (char comma[]{0, 0}; auto const& s : v)
        std::cout << comma << ' ' << std::quoted(s), comma[0] = ',';
    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

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