Re: [boost] Pimpl Again?

31 May 2016


      On Tue, May 31, 2016 at 2:45 PM, Rob Stewart  wrote:
...
On May 31, 2016 5:10:35 PM EDT, Emil Dotchevski 
wrote:
...
I'm not sure why
do you say that "my approach" doesn't support that. One possibility is
to use inheritance in the cpp file:
header:
struct foo { int critical_; };
shared_ptr<foo> create_foo();
inline void use_foo_critical( foo * p ) { ++p->critical_; }
void use_foo_not_so_critical( foo * )
Were you leaving encapsulation as an exercise for the reader?
class foo
{
public:
   use_critical () { ++critical_; }
protected:
   int critical_;
};
Your foo_ can still access critical_.
Right, though my preference is as follows.

//Public interface:

namespace boost { template <class> class shared_ptr; }
class foo;
boost::shared_ptr<foo> create_foo();
void use_foo_critical( foo * );
void use_foo_not_so_critical( foo * );

//Implementation details:

class foo
{
  foo( foo const & );
  foo & operator=( foo const & );
  int critical_;
  friend void use_foo_critical( foo * );
protected:
  foo();
  ~foo();
};
inline void use_foo_critical( foo * p ) { ++p->critical_; }

Emil