Re: [Boost-Users] boost::shared_ptr and NULL

From: Sean Shubin (sshubin_at_[hidden])
Date: 2002-05-14 03:25:53

As an alternative, I usually find that the "Introduce Null Object" refactoring results in simpler and more readable code overall.  Perhaps not as concise though.
  ----- Original Message ----- 
  From: Andrew R. Thomas-Cramer 
  To: Boost-Users_at_[hidden] 
  Sent: Monday, May 13, 2002 12:50 PM
  Subject: Re: [Boost-Users] boost::shared_ptr and NULL

  ----- Original Message -----
  From: "Peter Dimov" <pdimov_at_[hidden]>
  To: <Boost-Users_at_[hidden]>
  Sent: Monday, May 13, 2002 1:44 PM
  Subject: Re: [Boost-Users] boost::shared_ptr and NULL

  > From: "Andrew R. Thomas-Cramer" <artc_at_[hidden]>
  > >
  > > In this function declaration, is there a simpler way to express a null
  > shared pointer as the default argument value?
  > >   void foo( const boost::shared_ptr<T> & p = boost::shared_ptr<T>( ) );
  > >
  > > In this function call, is there a simpler way to express a null shared
  > pointer as the actual argument?
  > >   foo( boost::shared_ptr<T>( ) );
  >
  > No to both. In 1.27 boost::shared_ptr can be constructed from the literal 0,
  > but the constructor is explicit. In 1.28, the literal 0 is no longer a valid
  > argument to the constructor.

  Has there been any discussion in the past about supporting a more
  concise/readable value? E.g., the second call below appears more readable to me.
  (This particular example relies on "boost::null" being a class with a default
  constructor, and boost::shared_ptr providing a non-explicit constructor
  accepting a boost::null instance as an argument; this may be flawed.)

      foo( boost::shared_ptr<MyVeryLongClassName>() );
      foo( boost::null() );

        Yahoo! Groups Sponsor 
              ADVERTISEMENT
                
       
       

  Info: <http://www.boost.org>
  Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl>
  Unsubscribe: <mailto:boost-users-unsubscribe_at_[hidden]>

  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. 

[Non-text portions of this message have been removed]