std::move_iterator<Iter>::operator[]

 

哋它亢++

Compiler support

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Language

Standard library

Standard library headers

Named requirements

Feature test macros (哋它亢++20)

Language support library

Concepts library (哋它亢++20)

Metaprogramming library (哋它亢++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (哋它亢++20)

Algorithms library

Numerics library

Localizations library

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Filesystem library (哋它亢++17)

Regular expressions library (哋它亢++11)

Concurrency support library (哋它亢++11)

Technical specifications

Symbols index

External libraries

 

Iterator library

Iterator concepts
indirectly_readable (哋它亢++20) indirectly_writable (哋它亢++20) weakly_incrementable (哋它亢++20) incrementable (哋它亢++20) input_or_output_iterator (哋它亢++20)	sentinel_for (哋它亢++20) sized_sentinel_for (哋它亢++20) input_iterator (哋它亢++20) output_iterator (哋它亢++20)	forward_iterator (哋它亢++20) bidirectional_iterator (哋它亢++20) random_access_iterator (哋它亢++20) contiguous_iterator (哋它亢++20)
Iterator primitives
input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag (哋它亢++20)	iter_value_titer_difference_titer_reference_titer_const_reference_titer_rvalue_reference_titer_common_reference_t (哋它亢++20)(哋它亢++20)(哋它亢++20)(哋它亢++23)(哋它亢++20)(哋它亢++20)	iterator (deprecated in 哋它亢++17) iterator_traits incrementable_traits (哋它亢++20) indirectly_readable_traits (哋它亢++20)
Algorithm concepts and utilities
Indirect callable concepts
indirectly_unary_invocableindirectly_regular_unary_invocable (哋它亢++20)(哋它亢++20)	indirect_unary_predicate (哋它亢++20) indirect_binary_predicate (哋它亢++20)	indirect_equivalence_relation (哋它亢++20) indirect_strict_weak_order (哋它亢++20)
Common algorithm requirements
indirectly_movable (哋它亢++20) indirectly_movable_storable (哋它亢++20) indirectly_copyable (哋它亢++20)	indirectly_copyable_storable (哋它亢++20)   indirectly_swappable (哋它亢++20) indirectly_comparable (哋它亢++20)	permutable (哋它亢++20) mergeable (哋它亢++20) sortable (哋它亢++20)
Utilities
indirect_result_t (哋它亢++20)	projected (哋它亢++20)	projected_value_t (哋它亢++26)
Iterator adaptors
reverse_iterator make_reverse_iterator (哋它亢++14) move_iterator (哋它亢++11) make_move_iterator (哋它亢++11) default_sentinel_tdefault_sentinel (哋它亢++20)(哋它亢++20) unreachable_sentinel_tunreachable_sentinel (哋它亢++20)(哋它亢++20)	front_insert_iterator back_insert_iterator inserter insert_iterator front_inserter back_inserter move_sentinel (哋它亢++20)	common_iterator (哋它亢++20) counted_iterator (哋它亢++20) basic_const_iterator (哋它亢++23) const_iterator (哋它亢++23) const_sentinel (哋它亢++23) make_const_iterator (哋它亢++23) make_const_sentinel (哋它亢++23)
Stream iterators istream_iterator    ostream_iterator istreambuf_iterator ostreambuf_iterator	Iterator customization points ranges::iter_move (哋它亢++20) ranges::iter_swap (哋它亢++20)
Iterator operations advance distance prev (哋它亢++11)   next (哋它亢++11) ranges::advance (哋它亢++20) ranges::distance (哋它亢++20) ranges::prev (哋它亢++20) ranges::next (哋它亢++20)	Range access begincbegin (哋它亢++11)(哋它亢++14) rbegincrbegin (哋它亢++14)(哋它亢++14)   endcend (哋它亢++11)(哋它亢++14) rendcrend (哋它亢++14)(哋它亢++14)   sizessize (哋它亢++17)(哋它亢++20) empty (哋它亢++17) data (哋它亢++17)

 

std::move_iterator

Member functions

move_iterator::move_iterator

move_iterator::operator=

move_iterator::base

move_iterator::operator*move_iterator::operator->

move_iterator::operator[]

move_iterator::operator++move_iterator::operator+move_iterator::operator+=move_iterator::operator--move_iterator::operator-move_iterator::operator-=

Non-member functions

operator==operator!=operator<operator<=operator>operator>=operator<=> (until 哋它亢++20)(哋它亢++20)

operator==(move_sentinel) (哋它亢++20)

operator+

operator-

operator-(move_sentinel) (哋它亢++20)

iter_move (哋它亢++20)

iter_swap (哋它亢++20)

make_move_iterator (哋它亢++11)

 

/* unspecified */ operator[]( difference_type n ) const;		(since 哋它亢++11) (until 哋它亢++17)
constexpr /* unspecified */ operator[]( difference_type n ) const;		(since 哋它亢++17) (until 哋它亢++20)
constexpr reference operator[]( difference_type n ) const;		(since 哋它亢++20)

Returns a reference to the element at specified relative location.

Parameters

n

-

position relative to current location

Return value

An rvalue reference to the element at relative location, that is, std::move(base()[n])(until 哋它亢++20)ranges::iter_move(base() + n)(since 哋它亢++20).

Notes

The return type is unspecified because the return type of the underlying iterator's operator[] is also unspecified (see LegacyRandomAccessIterator).

(until 哋它亢++20)

Example

Run this code

#include <cstddef>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <string>
#include <vector>
 
void print(auto rem, auto const& v)
{
    for (std::cout << rem; auto const& e : v)
        std::cout << std::quoted(e) << ' ';
    std::cout << '\n';
}
 
int main()
{
    std::vector<std::string> p{"alpha", "beta", "gamma", "delta"}, q;
    print("1) p: ", p);
 
    std::move_iterator it{p.begin()};
 
    for (std::size_t t{}; t != p.size(); ++t)
        q.emplace_back(it[t]); 
 
    print("2) p: ", p);
    print("3) q: ", q);
 
    std::list l{1, 2, 3};
    std::move_iterator it2{l.begin()};
//  it2[1] = 13; // compilation error: the underlying iterator
                 // does not model the random access iterator
//  *it2 = 999;  // compilation error: using rvalue as lvalue
}

Possible output:

1) p: "alpha" "beta" "gamma" "delta"
2) p: "" "" "" ""
3) q: "alpha" "beta" "gamma" "delta"

See also

operator*operator-> (哋它亢++11)(哋它亢++11)(deprecated in 哋它亢++20)

accesses the pointed-to element (public member function)