intrusive_ptr aliasing constructor?

[schaumb]

Hi all,

I want to ask that is it reliable to implement intrusive_ptr aliasing constructor, similar to shared_ptr existing one?

Possible usage:

struct Test1 : boost::intrusive_ref_counter<Test1> {
  int a;
};

struct Test2 : boost::intrusive_ref_counter<Test2> {
  int b;
};

void fun(boost::intrusive_ptr<int> ctr);

auto iptr1 = boost::intrusive_ptr<Test1>(new Test1);
auto iptr2 = boost::intrusive_ptr<Test2>(new Test2);

fun( {iptr1, &iptr1->a} );
fun( {iptr2, &iptr2->b} );