Difference between revisions of "cpp/algorithm/move"
m (Use since= and until= params of {{dcl}} template.) |
(similar note as for copy_backward) |
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| + | ===Notes=== | ||
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| + | When moving overlapping ranges, {{tt|std::move}} is appropriate when moving to the left (beginning of the destination range is outside the source range) while {{tt|std::move_backward}} is appropriate when moving to the right (end of the destination range is outside the source range). | ||
===Example=== | ===Example=== | ||
Revision as of 13:38, 15 July 2013
| 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.
Contents |
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 | ||
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) |
converts the argument to an xvalue (function template) |
