在 C + + 中使用 std: : addressof()函数模板而不使用操作符 & 有什么好处吗？

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最佳答案

The unary operator& might be overloaded for class types to give you something other than the object's address, while std::addressof() will always give you its actual address.
Contrived example:

#include <memory>
#include <iostream>


struct A {
A* operator &() {return nullptr;}
};


int main () {
A a;
std::cout << &a << '\n';              // Prints 0
std::cout << std::addressof(a);       // Prints a's actual address
}

If you wonder when doing this is useful:
What legitimate reasons exist to overload the unary operator&?