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std::move_iterator::operator[](3) C++ Standard Libary std::move_iterator::operator[](3)

NAME

std::move_iterator::operator[] - std::move_iterator::operator[]

Synopsis


/*unspecified*/ operator[]( difference_type n ) const; (since C++11)
(until C++17)
constexpr /*unspecified*/ operator[]( difference_type n ) const; (since C++17)


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 C++20)
ranges::iter_move(base() + n)
(since C++20).

Example

// Run this code


#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 << 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 (size_t t{0U}; 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-> accesses the pointed-to element
(C++11) (public member function)
(C++11)(deprecated in C++20)

2022.07.31 http://cppreference.com