#include <iostream>
#include <new>
#include <memory>
#include <type_traits>
using namespace std;
 
struct PointerHolder {
	PointerHolder(const void * p) {
		cout << "Constructed Holder @ " << this << " with p == " << p << endl;
	}
 
	void * operator new(size_t, void * pp) { return pp; }
	const void * ptr{};
};
 
int main() {
	int z{};
	cout << "&z == " << &z << endl;
 
	PointerHolder p1(&z);
 
	auto buf = aligned_storage_t<sizeof(PointerHolder), alignof(PointerHolder)>{};
	auto p2 = ::new (&buf) PointerHolder(&z);
 
	// This doesn't compile
	// auto p3 = make_unique<PointerHolder>(&z);
 
	// And neither does this
	auto p4 = new (&buf) PointerHolder(&z);
	return 0;
}

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