Difference between revisions of "cpp/memory/destroy n"
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Revision as of 15:03, 15 June 2018
| 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 trueContents |
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 | ||
-ForwardIt must meet the requirements of LegacyForwardIterator.
| ||
-No increment, assignment, comparison, or indirection through valid instances of ForwardIt may throw exceptions.
| ||
Return value
The end of the range of objects that has been destroyed (i.e., std::next(first, n)).
Complexity
Linear in n.
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 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.
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; } |
Example
| This section is incomplete Reason: no example |
See also
| (C++17) |
destroys a range of objects (function template) |
| (C++17) |
destroys an object at a given address (function template) |
