iter_move(std::counted_iterator)

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Iterator library

Iterator concepts

indirectly_readable (C++20)
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Iterator primitives

input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag

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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)

iterator (deprecated in C++17)
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indirectly_unary_invocableindirectly_regular_unary_invocable

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indirectly_movable (C++20)
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(C++20)

(C++20)

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reverse_iterator
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move_iterator (C++11)
make_move_iterator (C++11)
default_sentinel_tdefault_sentinel (C++20)(C++20)
unreachable_sentinel_tunreachable_sentinel (C++20)(C++20)

front_insert_iterator
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inserter
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move_sentinel (C++20)

common_iterator (C++20)
counted_iterator (C++20)
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const_iterator (C++23)
const_sentinel (C++23)
make_const_iterator (C++23)
make_const_sentinel (C++23)

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istream_iterator
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ranges::iter_move (C++20)
ranges::iter_swap (C++20)

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sizessize (C++17)(C++20)
empty (C++17)
data (C++17)

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std::counted_iterator

Member functions
counted_iterator::counted_iterator
counted_iterator::operator=
counted_iterator::base
counted_iterator::count
counted_iterator::operator*counted_iterator::operator->
counted_iterator::operator[]
counted_iterator::operator++counted_iterator::operator++(int)counted_iterator::operator+counted_iterator::operator+=counted_iterator::operator--counted_iterator::operator--(int)counted_iterator::operator-counted_iterator::operator-=
Non-member functions
operator==operator<=> (C++20)(C++20)
operator==(default_sentinel_t) (C++20)
operator+ (C++20)
operator- (C++20)
operator-(default_sentinel_t) (C++20)
iter_move (C++20)
iter_swap (C++20)
Helper classes
iterator_traits<std::counted_iterator> (C++20)

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friendconstexpr decltype(auto) iter_move(conststd::counted_iterator& i) noexcept(noexcept(ranges::iter_move(i.base()))) requiresstd::input_iterator<I>;		(since C++20)

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

The function body is equivalent toreturnranges::iter_move(i.base());.

This function is not visible to ordinaryunqualified orqualified lookup, and can only be found byargument-dependent lookup whenstd::counted_iterator<I> is an associated class of the arguments.

Ifi.count() is equal to0, the behavior is undefined.

[edit]Parameters

a source iterator adaptor

[edit]Return value

An rvalue reference or a prvalue temporary.

[edit]Complexity

Constant.

[edit]Example

Run this code

#include <iomanip>#include <iostream>#include <iterator>#include <string>#include <vector> void print(autoconst& rem,autoconst& v){std::cout<< rem<<'['<< size(v)<<"] {";for(char comma[]{0,' ',0};autoconst& s: v)std::cout<< comma<<std::quoted(s),*comma=',';std::cout<<"}\n";} int main(){std::vector<std::string> p{"Alpha","Bravo","Charlie"}, q;    print("p", p);    print("q", q); using RI=std::counted_iterator<std::vector<std::string>::iterator>; for(RI iter{p.begin(),2}; iter!=std::default_sentinel;++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] {"", "", "Charlie"}q[2] {"Alpha", "Bravo"}

[edit]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 wasstd::iter_rvalue_reference_t<I>	changed todecltype(auto)

[edit]See also

iter_move (C++20)	casts the result of dereferencing an object to its associated rvalue reference type (customization point object)[edit]
iter_swap (C++20)	swaps the objects pointed to by two underlying iterators (function template)[edit]
move (C++11)	converts the argument to an xvalue (function template)[edit]
move_if_noexcept (C++11)	converts the argument to an xvalue if the move constructor does not throw (function template)[edit]
forward (C++11)	forwards a function argument and use the type template argument to preserve its value category (function template)[edit]
ranges::move (C++20)	moves a range of elements to a new location (algorithm function object)[edit]
ranges::move_backward (C++20)	moves a range of elements to a new location in backwards order (algorithm function object)[edit]