c++ - 对象初始化中是否允许指向 this 成员的指针？

Question

来自Aggregate initialization, set pointer to struct member ，以下代码合法吗:

struct S 
{
  int a;
  int* aptr;
};

S s = { 3, &s.a };

Answer 1

引用最新标准草案:

[basic.scope.pdecl]

The point of declaration for a name is immediately after its complete declarator ([dcl.decl]) and before its initializer (if any), except as noted below.

所以，是的。标识符 s 已被声明，因此可以在其初始化程序中使用。

请注意，s 的值只有在初始化后才能使用。示例中未使用该值，因此这不是问题。

I'd also be curious about whether analogous code is valid when the two members of S are in reversed order

成员的顺序并不重要。