std::rotate_copy
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <algorithm> | ||
| (1) | ||
| template< class ForwardIt, class OutputIt > OutputIt rotate_copy( ForwardIt first, ForwardIt n_first, | (until C++20) | |
| template< class ForwardIt, class OutputIt > constexpr OutputIt rotate_copy( ForwardIt first, ForwardIt n_first, | (since C++20) | |
| template< class ExecutionPolicy, class ForwardIt1, class ForwardIt2 > ForwardIt2 rotate_copy( ExecutionPolicy&& policy, ForwardIt1 first, ForwardIt1 n_first, | (2) | (since C++17) | 
1) Copies the elements from the range 
[first, last), to another range beginning at d_first in such a way, that the element n_first becomes the first element of the new range and n_first - 1 becomes the last element. 2) Same as (1), but executed according to 
policy. This overload only participates in overload resolution if  std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> is true| Contents | 
[edit] Parameters
| first, last | - | the range of elements to copy | 
| n_first | - | an iterator to an element in [first, last)that should appear at the beginning of the new range | 
| d_first | - | beginning of the destination range | 
| policy | - | the execution policy to use. See execution policy for details. | 
| Type requirements | ||
| - ForwardIt, ForwardIt1, ForwardIt2must meet the requirements ofForwardIterator. | ||
| - OutputItmust meet the requirements ofOutputIterator. | ||
[edit] Return value
Output iterator to the element past the last element copied.
[edit] Exceptions
The overload with a template parameter named ExecutionPolicy reports errors as follows:
-  If execution of a function invoked as part of the algorithm throws an exception and ExecutionPolicyis one of the three standard policies, std::terminate is called. For any otherExecutionPolicy, the behavior is implementation-defined.
- If the algorithm fails to allocate memory, std::bad_alloc is thrown.
[edit] Possible implementation
[edit] Example
Run this code
#include <algorithm> #include <vector> #include <iostream> int main() { std::vector<int> src = {1, 2, 3, 4, 5}; auto pivot = std::find(src.begin(), src.end(), 3); std::vector<int> dest(src.size()); std::rotate_copy(src.begin(), pivot, src.end(), dest.begin()); for (const auto &i : dest) { std::cout << i << ' '; } std::cout << '\n'; }
Output:
3 4 5 1 2
[edit] Complexity
linear in the distance between first and last
[edit] See also
| rotates the order of elements in a range (function template) | 


