std::destroy_at

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< cpp‎ | memory
 
 
 
Dynamic memory management
Uninitialized storage
destroy_at
(C++17)
Garbage collection support
Miscellaneous
(C++20)
(C++11)
(C++11)
C Library
Low level memory management
 
Defined in header <memory>
template< class T >
void destroy_at( T* p );
(since C++17)

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.

#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

See also

(C++17)
destroys a range of objects
(function template)
(C++17)
destroys a number of objects in a range
(function template)