| Defined in header |
||
template< class ForwardIt > |
(1) | (since C++17) (constexpr since C++20) |
| template< class ExecutionPolicy, class ForwardIt > |
(2) | (since C++17) |
1) Destroys the objects in the range [first, last), as if by
2) Same as (1), but executed according to policy. This overload participates in overload resolution only if all following conditions are satisfied:
| first, last | - | the pair of iterators defining the range of elements to destroy |
| policy | - | the execution policy to use |
| Type requirements | ||
-ForwardIt must meet the requirements of LegacyForwardIterator.
| ||
-No increment, assignment, comparison, or indirection through valid instances of ForwardIt may throw exceptions.
| ||
Linear in the distance between first and last.
The overload with a template parameter named ExecutionPolicy reports errors as follows:
ExecutionPolicy is one of the standard policies, std::terminate is called. For any other ExecutionPolicy, the behavior is implementation-defined.
template<class ForwardIt> constexpr // since C++20 void destroy(ForwardIt first, ForwardIt last) { for (; first != last; ++first) std::destroy_at(std::addressof(*first)); }
The following example demonstrates how to use destroy to destroy a contiguous sequence of elements.
Run this code
#include <iostream> #include <memory> #include <new> struct Tracer { int value; ~Tracer() { std::cout << value << " destructed\n"; } }; int main() { alignas(Tracer) unsigned char buffer[sizeof(Tracer) * 8]; for (int i = 0; i != 8; ++i) new(buffer + sizeof(Tracer) * i) Tracer{i}; // manually construct objects auto ptr = std::launder(reinterpret_cast<Tracer*>(buffer)); std::destroy(ptr, ptr + 8); }
Output:
0 destructed 1 destructed 2 destructed 3 destructed 4 destructed 5 destructed 6 destructed 7 destructed