Defined in header <algorithm> | ||
---|---|---|
template< class InputIt, class OutputIt > OutputIt move( InputIt first, InputIt last, OutputIt d_first ); | (since C++11) |
Moves the elements in the range [first, last)
, to another range beginning at d_first
. After this operation the elements in the moved-from range will still contain valid values of the appropriate type, but not necessarily the same values as before the move.
Parameters
first, last | - | the range of elements to move |
d_first | - | the beginning of the destination range. If d_first is within [first, last) , std::move_backward must be used instead of std::move. |
Type requirements | ||
- InputIt must meet the requirements of InputIterator . | ||
- OutputIt must meet the requirements of OutputIterator . |
Return value
Output iterator to the element past the last element moved (d_first + (last - first)
).
Complexity
Exactly last - first
move assignments.
Possible implementation
template<class InputIt, class OutputIt> OutputIt move(InputIt first, InputIt last, OutputIt d_first) { while (first != last) { *d_first++ = std::move(*first++); } return d_first; } |
Notes
When moving overlapping ranges, std::move
is appropriate when moving to the left (beginning of the destination range is outside the source range) while std::move_backward
is appropriate when moving to the right (end of the destination range is outside the source range).
Example
The following code moves thread objects (which themselves are not copyable) from one container to another.
#include <iostream> #include <vector> #include <list> #include <iterator> #include <thread> #include <chrono> void f(int n) { std::this_thread::sleep_for(std::chrono::seconds(n)); std::cout << "thread " << n << " ended" << '\n'; } int main() { std::vector<std::thread> v; v.emplace_back(f, 1); v.emplace_back(f, 2); v.emplace_back(f, 3); std::list<std::thread> l; // copy() would not compile, because std::thread is noncopyable std::move(v.begin(), v.end(), std::back_inserter(l)); for (auto& t : l) t.join(); }
Output:
thread 1 ended thread 2 ended thread 3 ended
See also
(C++11) | moves a range of elements to a new location in backwards order (function template) |
(C++11) | obtains an rvalue reference (function template) |
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