std::destroy_n
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                    | Defined in header  <memory> | ||
| template< class ForwardIt, class Size > ForwardIt destroy_n( ForwardIt first, Size n ); | (1) | (since C++17) | 
| template< class ExecutionPolicy, class ForwardIt, class Size > ForwardIt destroy_n( ExecutionPolicy&& policy, ForwardIt first, Size n ); | (2) | (since C++17) | 
1) Destroys the 
n objects in the range starting at first, as if by
for (; n > 0; (void) ++first, --n) std::destroy_at(std::addressof(*first));
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| Contents | 
[edit] Parameters
| first | - | the beginning of the range of elements to destroy | 
| n | - | the number of elements to destroy | 
| policy | - | the execution policy to use. See execution policy for details. | 
| Type requirements | ||
| - ForwardItmust meet the requirements ofForwardIterator. | ||
| -No increment, assignment, comparison, or indirection through valid instances of ForwardItmay throw exceptions. | ||
[edit] Return value
The end of the range of objects that has been destroyed (i.e., std::next(first, n)).
[edit] Complexity
Linear in n.
[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
| template<class ForwardIt, class Size> ForwardIt destroy_n( ForwardIt first, Size n ) { for (; n > 0; (void) ++first, --n) std::destroy_at(std::addressof(*first)); return first; } | 
[edit] Example
| This section is incomplete Reason: no example | 
[edit] See also
| (C++17) | destroys a range of objects (function template) | 
| (C++17) | destroys an object at a given address (function template) | 


