c++ - 为类重载运算符 new

Question

当我们重载类的 new 操作符时，我们将函数声明为成员函数。例如:

class OpNew {
public:
    OpNew() { cout << "OpNew::OpNew()" << endl;}
    void* operator new(size_t sz) {
         cout << "OpNew::new: "
            << sz << " bytes" << endl;
         return ::new char[sz];
    }
};

语句 OpNew *obj = new OpNew 如何在幕后工作？因为重载的 new 是 OpNew 类的成员，而不是静态的。那么编译器如何确保对 new 成员函数的调用成功呢？

Answer 1

An operator new() or operator new[]() for a class is always a static class member, even if it is not declared with the keyword static.

C++ 标准的内容(草案 n3242)，在 [class.free] 部分:

Any allocation function for a class T is a static member (even if not explicitly declared static).