Re: smart pointers

On 14 Feb, 13:57, Cholo Lennon <chololen...@hotmail.com> wrote:


I'm unclear exactly what non-copyable means in this context. The
following seems to copy just fine.

Here's part of a wrapper class for an MD5 hash I've been playing with
to get to grips with this pimpl stuff:

//-----------------------------------
#include <boost/scoped_ptr.hpp>
#include <stdint.h>
#include "hash.h"

class MD5Private;
class MD5 : public virtual Hash
{
public:
  using Hash::hash;
  using Hash::end;
  using Hash::digest;

  MD5();
  MD5(const MD5& h);
  MD5& operator= (const MD5& h) throw();
  virtual ~MD5() throw();

  virtual void begin () throw();
  virtual void hash (const uint8_t* data, const uint_32t& len)
throw();
  virtual void end (const uint8_t* hval) throw();

private:
  boost::scoped_ptr<MD5Private> p_;};

//--------------------------

and in the relevant bits of the class definition I currently have:

//--------------------------
class MD5Private {
public:
  uint32_t i[2];
  uint32_t buf[4];
  uint8_t in[64];
  uint8_t digest[16];

};

// New object, so initialise
MD5::MD5() : p_(new MD5Private()) { begin(); }

// Copy object, so do _not_ initialise
MD5::MD5(const MD5& other) :
  Hash(other),
  p_(other.p_.get() ? new MD5Private(*other.p_) : NULL)
{ }

MD5::~MD5() throw() { }

MD5&
MD5::operator= (const MD5& rhs) throw()
{
  MD5 temp(rhs);
  swap(p_, temp.p_);
  return *this;}

//<etc, etc>
//--------------------------

Are you saying that by using a boost::scoped_ptr this should not work?