std::swap_ranges

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Algorithm library

Constrained algorithms and algorithms on ranges(C++20)

Constrained algorithms, e.g.ranges::copy,ranges::sort, ...

Execution policies(C++17)

is_execution_policy

(C++17)

execution::seqexecution::parexecution::par_unseqexecution::unseq

(C++17) (C++17)(C++17)(C++20)

execution::sequenced_policyexecution::parallel_policyexecution::parallel_unsequenced_policyexecution::parallel_unsequenced

(C++17)(C++17)(C++17)(C++20)

Non-modifying sequence operations

(C++17)

all_ofany_ofnone_of (C++11) (C++11)(C++11)
countcount_if
mismatch
equal

findfind_iffind_if_not (C++11)
find_end
find_first_of
adjacent_find
search
search_n

Modifying sequence operations

Copy operations

copycopy_if (C++11)
copy_backward

copy_n (C++11)
move (C++11)
move_backward (C++11)

Swap operations

swap
iter_swap

swap_ranges

Transformation operations

replacereplace_if
transform

replace_copyreplace_copy_if

Generation operations

fill
fill_n

generate
generate_n

Removing operations

removeremove_if
unique

remove_copyremove_copy_if
unique_copy

Order-changing operations

reverse
reverse_copy
rotate
rotate_copy

random_shuffleshuffle (until C++17)(C++11)
shift_leftshift_right (C++20)(C++20)

Sampling operations

sample

(C++17)

Sorting and related operations

Partitioning operations

partition
partition_copy (C++11)
stable_partition

is_partitioned (C++11)
partition_point (C++11)

Sorting operations

sort
stable_sort
partial_sort
partial_sort_copy

is_sorted (C++11)
is_sorted_until (C++11)
nth_element

Binary search operations
(on partitioned ranges)

lower_bound
upper_bound

equal_range
binary_search

Set operations (on sorted ranges)

includes
set_union
set_intersection

set_difference
set_symmetric_difference

Merge operations (on sorted ranges)

merge

inplace_merge

Heap operations

push_heap
pop_heap
make_heap

sort_heap
is_heap (C++11)
is_heap_until (C++11)

Minimum/maximum operations

max
min
minmax (C++11)
clamp (C++17)

max_element
min_element
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Lexicographical comparison operations

lexicographical_compare

lexicographical_compare_three_way

(C++20)

Permutation operations

next_permutation
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is_permutation (C++11)

iota (C++11)
inner_product
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accumulate
reduce (C++17)
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partial_sum
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exclusive_scan (C++17)

transform_inclusive_scan (C++17)
transform_exclusive_scan (C++17)

Operations on uninitialized memory

uninitialized_copy
uninitialized_move (C++17)
uninitialized_fill

uninitialized_copy_n (C++11)
uninitialized_move_n (C++17)
uninitialized_fill_n

destroy (C++17)
destroy_n (C++17)
destroy_at (C++17)
construct_at (C++20)

uninitialized_default_construct (C++17)
uninitialized_value_construct (C++17)
uninitialized_default_construct_n (C++17)
uninitialized_value_construct_n (C++17)

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Defined in header`<algorithm>`
template<class ForwardIt1,class ForwardIt2> ForwardIt2 swap_ranges( ForwardIt1 first1, ForwardIt1 last1, ForwardIt2 first2);	(1)	(constexpr since C++20)
template<class ExecutionPolicy, class ForwardIt1,class ForwardIt2> ForwardIt2 swap_ranges( ExecutionPolicy&& policy, ForwardIt1 first1, ForwardIt1 last1, ForwardIt2 first2);	(2)	(since C++17)

1) Exchanges elements between range[first1, last1) and another range ofstd::distance(first1, last1) elements starting atfirst2.

2) Same as(1), but executed according topolicy.

This overload participates in overload resolution only if all following conditions are satisfied:

std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> istrue.	(until C++20)
std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>> istrue.	(since C++20)

If any of the following conditions is satisfied, the behavior is undefined:

The two ranges overlap.
There exists a pair of corresponding iteratorsiter1 anditer2 in the two ranges such that*iter1 is notSwappable with*iter2.

[edit]Parameters

first1, last1	-	the pair of iterators defining therange of elements to swap
first2	-	beginning of the second range of elements to swap
policy	-	theexecution policy to use
Type requirements
- `ForwardIt1, ForwardIt2` must meet the requirements ofLegacyForwardIterator.

[edit]Return value

Iterator to the element past the last element exchanged in the range beginning withfirst2.

[edit]Complexity

Exactlystd::distance(first1, last1) swaps.

[edit]Exceptions

The overload with a template parameter namedExecutionPolicy reports errors as follows:

If execution of a function invoked as part of the algorithm throws an exception andExecutionPolicy is one of thestandard 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]Notes

Implementations (e.g.MSVC STL) may enable vectorization when the iterator type satisfiesLegacyContiguousIterator and swapping its value type calls neither non-trivial special member function norADL-foundswap.

[edit]Possible implementation

template<class ForwardIt1,class ForwardIt2>constexpr//< since C++20ForwardIt2 swap_ranges(ForwardIt1 first1, ForwardIt1 last1, ForwardIt2 first2){for(; first1!= last1;++first1,++first2)std::iter_swap(first1, first2); return first2;}

[edit]Example

Demonstrates swapping of subranges from different containers.

Run this code

#include <algorithm>#include <iostream>#include <list>#include <vector> auto print=[](auto comment,autoconst& seq){std::cout<< comment;for(constauto& e: seq)std::cout<< e<<' ';std::cout<<'\n';}; int main(){std::vector<char> v{'a','b','c','d','e'};std::list<char> l{'1','2','3','4','5'};     print("Before swap_ranges:\n""v: ", v);    print("l: ", l);     std::swap_ranges(v.begin(), v.begin()+3, l.begin());     print("After swap_ranges:\n""v: ", v);    print("l: ", l);}

Output:

Before swap_ranges:v: a b c d el: 1 2 3 4 5After swap_ranges:v: 1 2 3 d el: a b c 4 5

[edit]See also

iter_swap	swaps the elements pointed to by two iterators (function template)[edit]
swap	swaps the values of two objects (function template)[edit]
ranges::swap_ranges (C++20)	swaps two ranges of elements (algorithm function object)[edit]