C++11 删除类类型？

Question

在 C++11 N3485 5.3.5.1 中它说:

The operand [of delete] shall be a pointer to object type or a class type. If of class type, the operand is contextually converted to a pointer to object type.

这种用法的例子是什么(操作数是类类型)？

Answer 1

If of class type, the operand is contextually implicitly converted to a pointer to object type.

因此，您可以在对象上使用 delete，但当且仅当此类型具有隐式转换运算符到指针时。

class A
{
public:
   class Inner {};
   A()
   {
      inner = new Inner();
   }
   operator Inner*() { return inner; }
private:
   Inner* inner;
};

int main()
{
   A* a = new A();
   delete *a;
   delete a;
}

不过，这不是 C++11 的新特性，在 C++03 标准中几乎有相同的词

The operand shall have a pointertype, or a class type having a single conversion function (12.3.2) to a pointer type.