std::destroy (3) - Linux Manuals

std::destroy: std::destroy


std::destroy - std::destroy


Defined in header <memory>
template< class ForwardIt > (1) (since C++17)
void destroy( ForwardIt first, ForwardIt last );
template< class ExecutionPolicy, class ForwardIt > (2) (since C++17)
void destroy( ExecutionPolicy&& policy, ForwardIt first, ForwardIt last );

1) Destroys the objects in the range [first, last), as if by

  for (; first != last; ++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.


first, last - the range 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



Linear in the distance between first and last.


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.

Possible implementation

  template< class ForwardIt >
  void destroy( ForwardIt first, ForwardIt last )
    for (; first != last; ++first)


The following example demonstrates how to use destroy to destroy a contiguous sequence of elements.
// Run this code

  #include <memory>
  #include <new>
  #include <iostream>

  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);



  0 destructed
  1 destructed
  2 destructed
  3 destructed
  4 destructed
  5 destructed
  6 destructed
  7 destructed

See also

destroy_n destroys a number of objects in a range
           (function template)

destroy_at destroys an object at a given address
           (function template)