Re: boost weak pointers and boost optional

On Jul 17, 11:21 am, Thant Tessman <thant.tess...@gmail.com> wrote:


Right. So how does user code look like?

1.

Optional opt = wp.lock();

if( shared_ptr<T>* p = boost::get< shared_ptr<T> >( &opt ) )
{
  // use **p
}
else
{
  // do not use p
}

2.

Optional opt = wp.lock();

try
{
  shared_ptr<T> const& r = boost::get< shared_ptr<T> >( opt );
  // use *r
}
catch( boost::bad_get )
{
  // ...
}

3.

struct visitor
{
  typedef void result_type;
  void operator()( shared_ptr<T> const & p ) const { ... }
  void operator()( nothing ) const { ... }
};

boost::apply_visitor( visitor(), wp.lock() );

Which one of these is an improvement?

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