* Alf P. Steinbach:
> * mod:
> { since lines in this posting are longer than recommended 70
> symbols, you can see some reformatting by the server or by your
> newsreading software. there are several links in the text, you
> might need to enter them into your browser manually. -mod }
OK, I'm reposting. Ironically, the reason for line length 80 in the
news client was to avoid problems with wrapping of headers when
processing clc++m articles for moderation. <ot>When do we, if ever,
get programs that do not try to "help" us by changing our data?</ot>
Original article text reformatted to 70 columns + added shortlinks:
-------------------------------------------------------------------
I just coded this up, and hopefully by mentioning it here I'll get
some useful feedback, like, bugs, shortcomings, improvements...
http://code.google.com/p/alfps/source/browse/trunk/alfs/pointers/AutoNewPtr.hpp
(http://preview.tinyurl.com/3puorr)
AutoNewPtr ("new" Berkeley open source license)
* Is not initialized with a raw pointer, but with constructor
arguments for the to-be referent: AutoNewPtr takes responsibility
for 'new'.
* By doing that, it has the ability to add a notifier to the created
object, so that the smart pointer gets notified when referred
object self-destructs, if it does (e.g., a window or file closing,
or a non-correctable error).
* After referred object destroyed, pointer re****ts that it's void
and throws on access via ->.
* Also, the default constructor sets the pointer to void state.
* Otherwise much like shared_ptr, except customization of deleter is
per type (via c++0x-like std::default_delete) rather than per
instance.
Since I haven't yet used this beast, other than testing the basic
functionality,
http://code.google.com/p/alfps/source/browse/trunk/test/pointers/auto_new_ptr/01/main.cpp
(http://preview.tinyurl.com/4vnv69),
I really don't know how it fares.
I suspect -> access is not the most efficient since it's checking
for voidness. But that shouldn't be a problem with e.g. files and
windows and such objects where this pointer would be relevant, I
think, and the main objective here is programmer productivity, not
efficiency.
It's not just one file (AutoNewPtr just wraps CheckedPtr, which uses
various things), so I think one would need the whole shebang, which
Google says
# Non-members may check out a read-only working copy anonymously
# over HTTP.
svn checkout http://alfps.googlecode.com/svn/trunk/
alfps-read-only
In there is also an adapted version of Howard Hinnants C++0x
unique_ptr emulation, and an adapted version of Turkani's (et.al.'s)
move_ptr. I'd hoped to be able to use unique_ptr instead of e.g.
auto_ptr, looking to the future! But unfortunately MSVC 7.1 doesn't
really like the unique_ptr code, and neither adaption has been used by
me for anything, or seriously tested by me. I will probably remove
these smart pointer adaptions. Just didn't think of it before putting
the code out there.
Praise and la****ngs and wild ideas all welcome.
Note that this is just freshly coded, it's currently more idea stuff
than anything else, but, might still be useful as-is!
Cheers,
- Alf
PS: Yes I'm aware that adding things to namespace std is formally
prohibited, except specializations of existing templates. The stuff
added is such things that will be added by C++0x. I think it's better
to just use namespace std than to keep changing code as things
migrate boost -> tr1 -> std.
--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?
[ See http://www.gotw.ca/resources/clcm.htm
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