std::move_iterator<Iter>::operator[]
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< cpp | iterator | move iterator
/* unspecified */ operator[]( difference_type n ) const; |
(constexpr since C++17) (until C++20) |
|
constexpr reference operator[]( difference_type n ) const; |
(since C++20) | |
Returns a reference to the element at specified relative location.
Contents |
[edit] Parameters
n | - | position relative to current location |
[edit] Return value
std::move(current
[n])(until C++20)ranges::iter_move(current
+ n)(since C++20)
[edit] Notes
The return type is unspecified because the return type of the underlying iterator's operator[] is also unspecified (see LegacyRandomAccessIterator). |
(until C++20) |
[edit] Example
Run this code
#include <cstddef> #include <iomanip> #include <iostream> #include <iterator> #include <list> #include <string> #include <vector> void print(auto rem, const auto& v) { for (std::cout << rem; const auto& 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"
[edit] See also
(C++11)(C++11)(deprecated in C++20) |
accesses the pointed-to element (public member function) |