function
<memory>

std::undeclare_no_pointers

void undeclare_no_pointers (char* p, size_t n);
Undeclare memory block as containing no pointers
Undeclares the range of memory described by p and n previously declared as containing no traceable pointer locations by a call to declare_no_pointers.

This function shall be called for all ranges declared with declare_no_pointers before the object containing the range is destroyed.

This does not restore the valitidy of dynamic objects previously invalidated by de the call to declare_no_pointers.

Parameters

p
Pointer to the first byte of the range.
This shall be the same value passed to a previous call to declare_pointers.
n
The length, expressed in bytes, of the range.
This shall be the same value passed to a previous call to declare_pointers.
size_t is an unsigned integral type.

Return value

none

This function throws no exceptions.

Example

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// declare_no_pointers / undeclare_no_pointers
#include <iostream>
#include <memory>

int main() {
  int * foo = new int(1);
  int * bar = new int(2);
  std::declare_no_pointers (reinterpret_cast<char*>(&bar),sizeof(int*));

  std::cout << "*foo: " << *foo << '\n';

  if (std::get_pointer_safety() != std::pointer_safety::strict)
    std::cout << "*bar: " << *bar << '\n';  // invalid if strict safety

  std::undeclare_no_pointers (reinterpret_cast<char*>(&bar),sizeof(int*));

  delete bar;
  delete foo;
  return 0;
}

Possible output:
*foo: 1
*bar: 2


See also