lack of implicit casting to T* and boost::shared_ptr::get()Does anyone know the reasons for the lack of an implicit casting
operator in any greater depth than:
A. Automatic conversion is believed to be too error prone.
(from the FAQ at the bottom of: http://www.boost.org/libs/smart_ptr/shared_ptr.htm)
Can anyone say specifically what about the implicit conversion would
be dangerous? I can think of a few things that would require care
about usage of smart pointers with implicit conversions, but nothing
that I would consider 'error-prone'.
In any language, there are implications and C++ certainly has its fair
share of other implicit behavio...
#include <boost/shared_ptr.hpp> or #include "boost/shared_ptr.hpp"?Is there a general rule/convention for when to use angle brackets and
when to use quotes in #include statements? Is the angle bracket reserved
for "system" header files (e.g. standard library headers), or is it for
general "stable" include files?
What about the grey areas in between these and actual application code,
e.g. headers for a library that is under my control but external to the
project being compiled?
I know both styles work, and in the case of the Boost headers I've seen
both of them used in example code, I'm just wondering if one is more
"c...
tr1::shared_ptr and boost::shared_ptrWhat was the justification for the tr1 shared_ptr not to allow a custom
deleter like the boost::shared_ptr?
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Axter wrote:
> What was the justification for the tr1 shared_ptr not to allow a custom
> deleter like the boost::shared_ptr?
>
There is none. It's part of the T...
What are the differences between std::shared_ptr and boost::shared_ptr?What are the differences between std::shared_ptr and boost::shared_ptr?
I just know they are, but don't know where.
Thanks.
* Kai Wen, on 14.09.2010 04:02:
> What are the differences between std::shared_ptr and boost::shared_ptr?
> I just know they are, but don't know where.
> Thanks.
Mostly none (except for the namespace), because std::shared_ptr was adopted from
boost::shared_ptr.
There may be a difference with respect to custom deleter replacement, and
perhaps with respect to conversions and perhaps also iostream operator<<
support, that is, that pe...
What are the differences between std::shared_ptr and boost::shared_ptr? #2I just know they are, but don't know where.
Thanks.
...
Problems mixing boost::lambda::bind and boost::shared_ptr..Hi,
Consider the following:
class A
{
public:
virtual bool foo() = 0;
};
class B : public A
{
public:
virtual bool foo() { return false; }
};
void fn()
{
std::list< A * > aList(10);
std::list< boost::shared_ptr<A> > aSharedList(10);
// This works fine..
std::count_if(
aList.begin(),
aList.end(),
boost::lambda::bind(A::foo, boost::lambda::_1)
);
// This doesn't compile..
std::count_if(
aSharedList.begin(),
aSharedList.end(),
boost::lambda::bind(A::foo, boost::lambda::_1)
);
}
--
Why doesn't the second ...
Get a gripnews:1109410871.2549642d5e49f40addbdb8eb5341c62a@1usenet
--
Dr. Harvie Wahl-Banghor <harvie_wahl-bangor@mindless.com>
gets a taste of his own medicine and squeals: "You
pathetic fag, you have to not only typo pounce but
edit it out of context. What a fucking lame ass bitch."
...
OSS awareness gets get healthy boost in South AfricaOSS gets the Shuttleworth treatment
Jason Norwood-Young May 12 2004 -
Public awareness of open source software is due to get a healthy boost
in South Africa over the next two years, thanks to the efforts of Mark
Shuttleworth, The Shuttleworth Foundation, HP and the CSIR.
[...]
"If nothing else, we hope to educate typical computer users about what
open source is," says Black. "Currently, end-users associate computers
with proprietary software because they've never known any different -
it's a very difficulty association to break.
Open Source software is such a differe...
boost::shared_ptr and polymorphismHi,
Is boost::shared_ptr polymorphic?
i.e., can i do safe downcasting using dynamic_cast?
Thanks.
bb wrote:
> Is boost::shared_ptr polymorphic?
>
> i.e., can i do safe downcasting using dynamic_cast?
Why ask? Why not just try and see FCOL? :-)
bb wrote:
>
> Is boost::shared_ptr polymorphic?
>
> i.e., can i do safe downcasting using dynamic_cast?
>
Almost. dynamic_cast itself won't work, because the compiler doesn't now
about the internals of shared_ptr. But you can use dymamic_pointer_cast,
which applies dynamic_cast to the stored pointer:
#i...
why boost:shared_ptr so slower?I've just done a performance test on the shared_ptr compared to the
native pointer case, the results show at lease 3 times slower when the
iteration number > 10000, this is the code snippet:
#include <vector>
#include <iostream>
#include <boost/shared_ptr.hpp>
using namespace std;
using namespace boost;
class Thing
{
public:
Thing()
{
}
void method (void)
{
int i = 5;
}
};
typedef boost::shared_ptr<Thing> ThingPtr;
void processThing(Thing* thing)
{
thing->method();
}
//loop1 and loop2 test shared_ptr in the vector container
void loop1(long lon...
Race in boost::shared_ptr?Is it only me who thinks that there is a race?
Here is a piece of code from boost_1_41_0\boost\smart_ptr\detail
\sp_counted_base_solaris.hpp, it implements simple reference counting
with basic-thread safety:
void release() // nothrow
{
if( atomic_dec_32_nv( &use_count_ ) == 0 )
{
dispose();
weak_release();
}
}
$man atomic_ops
NOTES
Atomic instructions ensure global visibility of atomically-
modified variables on completion. *In a relaxed store order
system, this does not guarantee that the vis...
Implementation of shared_ptr in boostWhile looking at the internal implementation of shared_ptr<>
I found the quoted function use_count(). What I don't understand
is the following
What is the rational of the static_cast in it? Has it something
to do with avoiding to cache that value? How is this
different to simply returning the member use_count_?
Thanks for any explanations
Ali
namespace boost {
namespace detail{
class sp_counted_base {
private:
long use_count_; // #shared
public:
long use_count() const // nothrow
{
return static_cast<long const volatile &>( use_count_ )...
Doubt about boost shared_ptrHi all,
I have a query regarding the exchanging of a
boost::shared_ptr beween different threads. In my program i've two
threads both of which having their own internal queues for storing the
shared_ptr. one thread is meant to pass the shared_ptr to another after
its processing.
So when a message arrives i convert it into a class of
my own called 'Msg' and i put the 'Msg' object pointer into a
shared_ptr and put into the other thread's message queue. in that
second thread after starting the processing suddenly the program stops
responding. wh...
How to get boost date_time?I have downloaded boost throught synaptic to Ubuntu 7.04. But I don't
have the folder date_time in my /usr/inculde/boost dir. How do I get
date_time?
desktop wrote:
> I have downloaded boost throught synaptic to Ubuntu 7.04. But I don't
> have the folder date_time in my /usr/inculde/boost dir. How do I get
> date_time?
you are OT. anyway, sudo apt-get install libboost-date-time-dev
Regards,
Zeppe
On 14 Jun, 11:58, desktop <f...@sss.com> wrote:
> I have downloaded boost throught synaptic to Ubuntu 7.04. But I don't
> have the folder date_time in my /usr...
GET YOUR MORNING BOOSThttp://tinyurl.com/7xl3xey
http://www.ebay.com/itm/251080697697?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
...
question about boost::shared_ptrI am asking this question here because I did search for a boost NG but
couldn't find one. My question is this:
Say I have something like
boost::shared_ptr<Base_Class> null_ptr;
boost::shared_ptr<Base_Class> test_ptr( new Derived_From_Base_Class );
vector<boost::shared_ptr<Base_Class> > test_vector;
test_vector.push_back( test_ptr );
how would I go about explicitly removing the object test_ptr points to?
Would something like this work?
test_vector[0] = null_ptr;
test_ptr.reset();
If I manually call the dtor (something I have been warned should almost
never be do...
Getting to grips with cookiesHi all. I have never used cookis on my website. I am trying to test
for a cookie and if one is not there set one. I can see all my IE
cookies together with the date. I am deleting the cookie each time and
a new one is added with the latest time against it. The problem is the
value of the cookie is not changing as it should. Any sugestions on
this. It does work in FF, but not in IE8
*** Code ***
<?php
if (isset($_COOKIE['History']))
{
echo ("Cookie = " . $_COOKIE["History"]);
}
else
{
$time = time();
setcookie("History", $time);
echo $time;
}
?...
boost::shared_ptrIf a method is declared to return a type boost::shared_ptr<sometype>,
how can the method be changed to do the equivalent of returning NULL
when it was declared to return a raw pointer?
* Christopher:
> If a method is declared to return a type boost::shared_ptr<sometype>,
> how can the method be changed to do the equivalent of returning NULL
> when it was declared to return a raw pointer?
Return boost::shared_ptr<sometype>().
Hm.
I'm amazed about some of the questions here. Please read the manual
before posting. Or at least, /glance/ at it.
Cheers, &...
boost::shared_ptr revisited again
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I have posted my news about one week ago, it still doesn't appear on the
newsgroup.
I'm not sure, what is reason for that -- I haven't received any answer,
maybe because
of my e-mail address was spammers-protected (although my post contained
signature with
way of decoding my ...
Getting to grips with the fsiG'day
Here's a newbie question from an old hand...
I've done very little with D3/NT previously. All the real work seems to
be done on *nix. Anyway. Be that as it may...
I'm writing some software that will use a large static data file. The
VME I have is way too small for it so I am getting into creating and
using an fsi file for the first time. The question is : How do I do it?
;-)
I've used the File Manager to create a domain and created a table
within it. Not sure I've done it right so far - kind of feeling my way
here. I can't seem to find any re...
Getting to Grips with VistaMessage-ID: <foipmt$9tb$01$1@news.t-online.com>
[quote]
I myself run W2K in a virtual machine, and it is my base windows install
which I use for all windows development (which now mainly is compiling and
debugging on it. *Writing* the stuff is done on linux, in KDevelop
The poor WinXP laptop gets switched on very rarely, to test if all stuff
runs OK on XP too (it *does* happen that the two react slightly different,
and it is difficult to find and program around if they do)
In my opinion, W2K was the best windows ever, far better than XP, and not to
mention this garbage they named Vista...
Getting to grips with Linux
Nice BBC article for you to comment on. Balanced and says pretty much
what anyone with common sense and a feeling for real peoples need say.
http://news.bbc.co.uk/1/hi/technology/7594249.stm
,----
| First impressions of Linux were positive. The new machine, an Asus Eee,
| came pre-installed with a distribution, or flavour, of Linux called
| Xandros.
`----
,----
| The music management program - its "iTunes", if you like - let me listen
| to music and podcasts on my new laptop but wouldn't sync anything I
| loaded on to my iPod. Big problem for a music and podcast junkie.
`--...
Getting to grips with SATAI got a Maxtor 120Gig SATA HDD, boots up fine when it's the only drive
on my computer. The BIOS (Award) is set to HDD-0.
Now, I'd like to install my old 60Gig Seagate as a Slave (was the
Master) so I can access the data.
I set the jumpers on it for Slave operation, but booting up the computer
fails when the Seagate is attached. It seems to want to boot from the
old drive, even though it is set as Slave.
I tried cabling it up to the primary, and also tried secondary IDE
header, as HDD-1 and various other selections, to no avail.
I downloaded and installed the last BIOS upg...
How to detect NULL for boost:shared_ptrHi,
I am playing with boost pointer and try to wrap the following codes
A* func(){
...
if(condition 1 ){
return a;
}
else
return NULL;
}
Now I wrap a as shared_ptr(new A()) and change funcion as share_ptr<A>
func();
The problem is that shared_ptr will not accept NULL.
How should I do it in this case?
Thanks
Chris
tradevol@yahoo.com wrote:
> I am playing with boost pointer and try to wrap the following codes
>
> A* func(){
> ...
> if(condition 1 ){
> return a;
> }
> else
> return NULL;
>
> }
>
> Now I...
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