From cppreference.com
Defined in header
template<classForwardIt,classOutputIt>OutputItrotate_copy(ForwardItfirst,ForwardItmiddle,ForwardItlast,OutputItd_first); (1)(constexpr since C++20)template<classExecutionPolicy,classForwardIt1,classForwardIt2>ForwardIt2rotate_copy(ExecutionPolicy&&policy,ForwardIt1first,ForwardIt1middle,ForwardIt1last,ForwardIt2d_first); (2) (since C++17)1) Copies elements from the source range [first, last) to the destination range beginning at d_first in rotated order. In the destination range, the elements originally in [first, middle) are placed after the elements originally in [middle, last) while the orders of the elements in both ranges are preserved.
2) Same as (1), but executed according to policy.
This overload participates in overload resolution only if the value of the following expression is true:
std::is_execution_policy_v<std::decay_t<ExecutionPolicy>>
(until C++20)std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>>
(since C++20)If any of the following conditions is satisfied, the behavior is undefined:
[first, middle) or [middle, last) is not a
.
The source and destination ranges overlap.
Parameters
first, last - the pair of iterators defining the source
middle - the beginning of the part that should appear at the beginning of the destination range d_first - the beginning of the destination range policy - the
to use Type requirements -ForwardIt, ForwardIt1, ForwardIt2 must meet the requirements of
. -OutputIt must meet the requirements of
. Return value
The past-the-end iterator of the destination range.
Complexity
Exactly std::distance(first,last) assignments.
Exceptions
2) During the execution process:
If the temporary memory resources required for parallelization are not available,
is thrown.
If an uncaught exception is thrown while accessing objects via an algorithm argument, the behavior is determined by the execution policy (for
,
is invoked).
Possible implementation
See also the implementations in
,
, and
.
template<classForwardIt,classOutputIt>constexpr// since C++20OutputItrotate_copy(ForwardItfirst,ForwardItmiddle,ForwardItlast,OutputItd_first){d_first=std::copy(middle,last,d_first);returnstd::copy(first,middle,d_first);}Example
Run this code
#include<algorithm>#include<iostream>#include<iterator>#include<vector>intmain(){std::vector<int>src{1,2,3,4,5};std::vector<int>dest(src.size());autopivot=std::find(src.begin(),src.end(),3);std::rotate_copy(src.begin(),pivot,src.end(),dest.begin());for(inti:dest)std::cout<<i<<' ';std::cout<<'\n';// copy the rotation result directly to the std::coutpivot=std::find(dest.begin(),dest.end(),1);std::rotate_copy(dest.begin(),pivot,dest.end(),std::ostream_iterator<int>(std::cout," "));std::cout<<'\n';}Output:
3 4 5 1 2 1 2 3 4 5 See also