< cpp‎ | algorithm
Algorithm library
Constrained algorithms and algorithms on ranges (C++20)
Constrained algorithms, e.g. ranges::copy, ranges::sort, ...
Execution policies (C++17)
Non-modifying sequence operations
Modifying sequence operations
Partitioning operations
Sorting operations
Binary search operations
Set operations (on sorted ranges)
Heap operations
Minimum/maximum operations

Numeric operations
Operations on uninitialized storage
C library
Defined in header <algorithm>
template< class BidirIt, class OutputIt >
OutputIt reverse_copy( BidirIt first, BidirIt last, OutputIt d_first );
(until C++20)
template< class BidirIt, class OutputIt >
constexpr OutputIt reverse_copy( BidirIt first, BidirIt last, OutputIt d_first );
(since C++20)
template< class ExecutionPolicy, class BidirIt, class ForwardIt >

ForwardIt reverse_copy( ExecutionPolicy&& policy,

                        BidirIt first, BidirIt last, ForwardIt 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 elements in the new range are in reverse order.
Behaves as if by executing the assignment *(d_first + (last - first) - 1 - i) = *(first + i) once for each non-negative i < (last - first).
If the source and destination ranges (that is, [first, last) and [d_first, d_first+(last-first)), respectively) overlap, the behavior is undefined.
2) Same as (1), but executed according to policy. This overload does not participate in overload resolution unless

std::is_execution_policy_v<std::decay_t<ExecutionPolicy>> is true.

(until C++20)

std::is_execution_policy_v<std::remove_cvref_t<ExecutionPolicy>> is true.

(since C++20)


[edit] Parameters

first, last - the range of elements to copy
d_first - the beginning of the destination range
Type requirements
BidirIt must meet the requirements of LegacyBidirectionalIterator.
OutputIt must meet the requirements of LegacyOutputIterator.
ForwardIt must meet the requirements of LegacyForwardIterator.

[edit] Return value

Output iterator to the element past the last element copied.

[edit] Complexity

Exactly last - first assignments.

[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 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.

[edit] Notes

Implementations (e.g. MSVC STL) may enable vectorization when the both iterator types satisfy LegacyContiguousIterator and have the same value type, and the value type is TriviallyCopyable.

[edit] Possible implementation

See also the implementations in libstdc++, libc++, and MSVC STL.

template<class BidirIt, class OutputIt>
constexpr // since C++20
OutputIt reverse_copy(BidirIt first, BidirIt last, OutputIt d_first)
    for (; first != last; ++d_first)
        *d_first = *(--last);
    return d_first;

[edit] Example

#include <algorithm>
#include <iostream>
#include <vector>
int main()
    auto print = [](std::vector<int> const& v)
        for (const auto& value : v)
            std::cout << value << ' ';
        std::cout << '\t';
    std::vector<int> v({1,2,3});
    std::vector<int> destination(3);
    std::reverse_copy(std::begin(v), std::end(v), std::begin(destination));
    std::reverse_copy(std::rbegin(v), std::rend(v), std::begin(destination));


1 2 3   3 2 1   1 2 3

[edit] See also

reverses the order of elements in a range
(function template) [edit]
creates a copy of a range that is reversed
(niebloid) [edit]