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// addressof example
#include <iostream>
#include <memory>
struct unreferenceable {
int x;
unreferenceable* operator&() { return nullptr; }
};
void print (unreferenceable* m) {
if (m) std::cout << m->x << '\n';
else std::cout << "[null pointer]\n";
}
int main () {
void(*pfn)(unreferenceable*) = std::addressof(print);
unreferenceable val {10};
unreferenceable* foo = &val;
unreferenceable* bar = std::addressof(val);
(*pfn)(foo); // prints [null pointer]
(*pfn)(bar); // prints 10
return 0;
}
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