Re: [Boost-users] scoped_ptr::release (again)

On 24 Feb 2009, at 19:26, Matthieu Brucher wrote:

2009/2/24 Steven Watanabe :

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AMDG

Nat Goodspeed wrote:

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Christopher Jefferson wrote:

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I'd vote for keeping scoped_ptr as simple as possible, even removing that swap, and directing people who want more power to unique_ptr.

I'd like to keep swap(). If the coder wants to disable it, wouldn't 'const scoped_ptr' suffice?

If I have a class that supports assignment, and my class uses scoped_ptr to manage some resource, Herb Sutter's exception-safe assignment operator still applies:

1. Construct a new stack scoped_ptr with the incoming resource. An exception here leaves *this unmolested. 2. Swap the member scoped_ptr with the new scoped_ptr. (swap() is guaranteed not to throw.) 3. Leaving the assignment-operator method body destroys the temp stack scoped_ptr, releasing the member scoped_ptr's previous data.

The question is not whether swap is useful, but whether it should be part of scoped_ptr rather than another smart pointer.

In Christ, Steven Watanabe

Which other smart pointer? Scoped_* is really simple and the optimized code is the same as a naked pointer, which is what some people need. For me, scoped_* is exactly what I need: - RAII - tantamount to a simple pointer - possible to swap pointers

unique_ptr offers exactly that set too, along with: - possible to move pointers. - ability to use custom deleter if you want (I don't know if scoped_ptr offers that.. it is zero overhead if you don't use it). The only reasons to use scoped_ptr over unique_ptr, once it is present, will be if you don't want to be able to move things around. Probably the nicest feature of unique_ptr of scoped_ptr is that it can be returned from functions. Chris