std::reverse (3) - Linux Man Pages
Defined in header <algorithm>
template< class BidirIt > (until C++20)
void reverse( BidirIt first, BidirIt last );
template< class BidirIt > (1) (since C++20)
constexpr void reverse( BidirIt first, BidirIt last );
template< class ExecutionPolicy, class BidirIt > (2) (since C++17)
void reverse( ExecutionPolicy&& policy, BidirIt first, BidirIt last );
1) Reverses the order of the elements in the range [first, last)
Behaves as if applying std::iter_swap to every pair of iterators first+i, (last-i) - 1 for each non-negative i < (last-first)/2
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
BidirIt must meet the requirements of ValueSwappable and LegacyBidirectionalIterator.
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.
See also the implementations in libstdc++ and libc++.
Exactly (last - first)/2 swaps.
// Run this code