Re: [Boost-users] [Smart Ptr] Why is weak_ptr a _ptr?

Subject: Re: [Boost-users] [Smart Ptr] Why is weak_ptr a _ptr?
From: Peter Dimov (pdimov_at_[hidden])
Date: 2010-10-13 10:30:41

Szymon Gatner wrote:

> Is it just me or is it really the worse naming in whole boost library?
>
> It is nothing like any other smart pointer.
>
> No initialization / construction from raw pointer.
>
> No operator * or -> (the very least one would expect from _ptr class).
>
> No get().

The weak pointer concept originates from garbage-collected languages that 
have pointers, such as some proposed extensions to C/C++. In such a 
language, a weak_ptr can be constructed from a raw pointer, can have *, ->, 
does have get() -- because the raw pointers are "strong", that is, they keep 
an object from being destroyed because the garbage collector tracks all 
pointers.

(See for example section 5.4 in 
http://www.usenix.org/publications/library/proceedings/c++94/full_papers/ellis.a )

In our "ordinary" C++, the equivalent of such a garbage-collected raw 
pointer is shared_ptr, which is why weak_ptr can only give you a shared_ptr 
and not a raw pointer.