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;
}
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Possible output: