std::destroy_at (3) - Linux Manuals

std::destroy_at: std::destroy_at

NAME

std::destroy_at - std::destroy_at

Synopsis

Defined in header <memory>
template< class T > (since C++17)
void destroy_at( T* p );

Calls the destructor of the object pointed to by p, as if by p->~T().

Parameters

p - a pointer to the object to be destroyed

Return value

(none)

Possible implementation

  template<class T>
  void destroy_at(T* p)
  {
      p->~T();
  }

Example

The following example demonstrates how to use destroy_at 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));

      for (int i = 0; i < 8; ++i)
          std::destroy_at(ptr + i);

  }

Output:

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