Re: [boost] [valid_ptr] proposing a new type of pointer object that allows validity tracking without memory management and object ownership

Subject: Re: [boost] [valid_ptr] proposing a new type of pointer object that allows validity tracking without memory management and object ownership
From: Gruenke, Matt (mgruenke_at_[hidden])
Date: 2011-03-16 19:14:40

"Non-NULL" is different than "valid".  Maybe such a thing should be called nonnull_ptr<>?  In the case of passive_ptr<>, I do allow it to be NULL.  While a nonnull_ptr<> would useful, it would only cover some of the cases in which I use passive_ptr<>.

I don't see why you'd have to check for NULL upon copy or assignment from another nonnull_ptr<>.  It only needs to check in the constructor and when the value is directly changed.  In fact, aside from that runtime check and the ability to alter the value, I don't really see what it buys you over using a reference.  Also, whether the value is NULL is orthogonal to ownership - I could imagine having a nonnull_shared_ptr<>, nonnull_scoped_ptr<>, etc.

Matt

-----Original Message-----
From: Klaim - Joël Lamotte [mailto:mjklaim_at_[hidden]]
Sent: Wed 3/16/2011 6:37 PM
To: boost_at_[hidden]
Cc: Gruenke, Matt
Subject: Re: [boost] [valid_ptr] proposing a new type of pointer object that allows validity tracking without memory management and object ownership
 
As far as I understand, it's only a type working like a raw pointer but with
checks on assignation and copy. Those checks will only assume that the
pointer don't have a NULL value, (or maybe points to an adress that i'snt
possible?)

is it correct understanding of this library?

Joël Lamotte.