std::rotate_copy

 

C++

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Concepts library(C++20)

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Technical Specifications

 

Algorithm library

Constrained algorithms and algorithms on ranges (C++20)
Concepts and utilities: std::Sortable, std::projected, ...
Constrained algorithms: std::ranges::copy, std::ranges::sort, ...
Execution policies (C++17)
is_execution_policy	execution::seqexecution::parexecution::par_unseqexecution::unseq (C++20)	execution::sequenced_policyexecution::parallel_policyexecution::parallel_unsequenced_policyexecution::parallel_unsequenced (C++20)
Non-modifying sequence operations
all_ofany_ofnone_of (C++11)(C++11)(C++11) for_each for_each_n (C++17)	countcount_if mismatch equal adjacent_find	findfind_iffind_if_not (C++11) find_end find_first_of	search search_n lexicographical_compare lexicographical_compare_3way (C++20)
Modifying sequence operations
copycopy_if (C++11) copy_n (C++11) copy_backward move (C++11) move_backward (C++11) shift_leftshift_right (C++20)(C++20) transform	fill fill_n generate generate_n swap iter_swap swap_ranges sample (C++17)	removeremove_if replacereplace_if reverse rotate unique random_shuffle (until C++17)	remove_copyremove_copy_if replace_copyreplace_copy_if reverse_copy rotate_copy unique_copy shuffle (C++11)
Operations on uninitialized storage
uninitialized_copy uninitialized_move (C++17) uninitialized_fill	uninitialized_copy_n (C++11) uninitialized_move_n (C++17) uninitialized_fill_n	uninitialized_default_construct (C++17) uninitialized_value_construct (C++17) destroy (C++17)	uninitialized_default_construct_n (C++17) uninitialized_value_construct_n (C++17) destroy_n (C++17)
Partitioning operations
is_partitioned (C++11) partition_point (C++11)	partition partition_copy (C++11)	stable_partition
Sorting operations
is_sorted (C++11) is_sorted_until (C++11)	sort stable_sort	partial_sort partial_sort_copy	nth_element
Binary search operations
lower_bound	upper_bound	binary_search	equal_range
Set operations (on sorted ranges)
merge inplace_merge	set_difference set_intersection	set_symmetric_difference set_union	includes
Heap operations
is_heap (C++11) is_heap_until (C++11)	make_heap sort_heap	push_heap pop_heap
Minimum/maximum operations
max max_element	min min_element	minmax (C++11) minmax_element (C++11)	clamp (C++17) compare_3way (C++20)
Permutations
is_permutation (C++11)	next_permutation	prev_permutation
Numeric operations
iota (C++11) inner_product adjacent_difference	accumulate reduce (C++17) transform_reduce (C++17)	partial_sum inclusive_scan (C++17) exclusive_scan (C++17)	transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
C library
qsort	bsearch

 

Defined in header <algorithm>
	(1)
template<class ForwardIt, class OutputIt > OutputIt rotate_copy( ForwardIt first, ForwardIt n_first,                       ForwardIt last, OutputIt d_first );			(until C++20)
template<class ForwardIt, class OutputIt > constexpr OutputIt rotate_copy( ForwardIt first, ForwardIt n_first,                                 ForwardIt last, OutputIt d_first );			(since C++20)
template<class ExecutionPolicy, class ForwardIt1, class ForwardIt2 > ForwardIt2 rotate_copy( ExecutionPolicy&& policy, ForwardIt1 first, ForwardIt1 n_first,                       ForwardIt1 last, ForwardIt2 d_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

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, ForwardIt2 must meet the requirements of LegacyForwardIterator.
- OutputIt must meet the requirements of LegacyOutputIterator.

Return value

Output iterator to the element past the last element copied.

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 ExecutionPolicy is one of the standard policies, std::terminate is called. For any other ExecutionPolicy, the behavior is implementation-defined.
• If the algorithm fails to allocate memory, std::bad_alloc is thrown.

Possible implementation

See also the implementations in libstdc++ and libc++.

template<class ForwardIt, class OutputIt> OutputIt rotate_copy(ForwardIt first, ForwardIt n_first, ForwardIt last, OutputIt d_first){ d_first =std::copy(n_first, last, d_first);returnstd::copy(first, n_first, d_first);}

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(constauto&i : dest){std::cout<< i <<' ';}std::cout<<'\n';}

Output:

3 4 5 1 2

Complexity

linear in the distance between first and last

See also

rotate

rotates the order of elements in a range (function template)