auto_ptr

Hi,

Is the following safe? (it works fine and to me it looks exception
safe!).

void thirdPartyLibFun(T* t) {
...
}

void myFun() {
std::auto_ptr<Tap2t = std::auto_ptr<T>(new T);

thirdPartyLibFun(ap2t.get());
}

Thanks.

bb wrote:

Quote:

Hi,
>
Is the following safe? (it works fine and to me it looks exception
safe!).
>
void thirdPartyLibFun(T* t) {
...
}
>
void myFun() {
std::auto_ptr<Tap2t = std::auto_ptr<T>(new T);

Try direct initialization, lose the cast.

Quote:

>
thirdPartyLibFun(ap2t.get());
}
>

This isn't @*^&@! JAVA. If you want a local object, use a
local object.

void myFun() {
T x;
thirdPartyLibFun(&x);
}

Plenty exception safe and a bit more efficient.

bb wrote:

Quote:

Hi,
>
Is the following safe? (it works fine and to me it looks exception
safe!).
>
void thirdPartyLibFun(T* t) {
...
}
>
void myFun() {
std::auto_ptr<Tap2t = std::auto_ptr<T>(new T);
>
thirdPartyLibFun(ap2t.get());
}
>
Thanks.
>

What's wrong with:

void myFun() {
std::auto_ptr<Tap2t(new T);
thirdPartyLibFun(ap2t.get());
}

Or (even better IMO):

void myFun() {
T t;
thirdPartyLibFun(&t);
}

--
Clark S. Cox III
clarkcox3@gmail.com

Ron Natalie wrote:

Quote:

bb wrote:
>

Quote:

>Hi,
>>
>Is the following safe? (it works fine and to me it looks exception
>safe!).
>>
> void thirdPartyLibFun(T* t) {
> ...
> }
>>
> void myFun() {
> std::auto_ptr<Tap2t = std::auto_ptr<T>(new T);

>
>
Try direct initialization, lose the cast.
>

Quote:

>>
> thirdPartyLibFun(ap2t.get());
> }

>
>
This isn't @*^&@! JAVA. If you want a local object, use a
local object.
>
void myFun() {
T x;
thirdPartyLibFun(&x);
}
>
Plenty exception safe and a bit more efficient.

Do you hae the souce code for thirdPartyLibFun(T *t)? What if it
deletes the T that is pointed to?

LR

LR wrote:

Quote:

Ron Natalie wrote:

Quote:

>bb wrote:
>>

Quote:

>>Hi,
>>>
>>Is the following safe? (it works fine and to me it looks exception
>>safe!).
>>>
>> void thirdPartyLibFun(T* t) {
>> ...
>> }
>>>
>> void myFun() {
>> std::auto_ptr<Tap2t = std::auto_ptr<T>(new T);

>>
>>
>Try direct initialization, lose the cast.
>>

Quote:

>>>
>> thirdPartyLibFun(ap2t.get());
>> }

>>
>>
>This isn't @*^&@! JAVA. If you want a local object, use a
>local object.
>>
> void myFun() {
> T x;
> thirdPartyLibFun(&x);
> }
>>
>Plenty exception safe and a bit more efficient.

>
Do you hae the souce code for thirdPartyLibFun(T *t)? What if it
deletes the T that is pointed to?

In that case, the original code with auto_ptr would note fare any better:
instead of deleting non-allocated memory, it would double deallocate
allocated memory.

Best

Kai-Uwe Bux

LR <lruss@superlink.netwrote:

Quote:

Ron Natalie wrote:

Quote:

>This isn't @*^&@! JAVA. If you want a local object, use a
>local object.
>>
> void myFun() {
> T x;
> thirdPartyLibFun(&x);
> }
>>
>Plenty exception safe and a bit more efficient.

>
Do you hae the souce code for thirdPartyLibFun(T *t)?
What if it deletes the T that is pointed to?

If it does there is trouble anyway. An auto_ptr shouldn't
point to an object that gets deleted by something else.
Consider what would happen if the deleted memory
was reallocated for some other purpose - the auto_ptr
would have no clue and still attepmt to delete it.

LR wrote:

Quote:

Ron Natalie wrote:

Quote:

>bb wrote:
>>

Quote:

>>Hi,
>>>
>>Is the following safe? (it works fine and to me it looks exception
>>safe!).
>>>
>> void thirdPartyLibFun(T* t) {
>> ...
>> }
>>>
>> void myFun() {
>> std::auto_ptr<Tap2t = std::auto_ptr<T>(new T);

>>
>>
>Try direct initialization, lose the cast.
>>

Quote:

>>>
>> thirdPartyLibFun(ap2t.get());
>> }

>>
>>
>This isn't @*^&@! JAVA. If you want a local object, use a
>local object.
>>
> void myFun() {
> T x;
> thirdPartyLibFun(&x);
> }
>>
>Plenty exception safe and a bit more efficient.

>
Do you hae the souce code for thirdPartyLibFun(T *t)? What if it
deletes the T that is pointed to?
>
LR

Then the code is broken regardless of auto_ptr's involvement.

--
Clark S. Cox III
clarkcox3@gmail.com

auto_ptr

re: auto_ptr

re: auto_ptr

re: auto_ptr

re: auto_ptr

re: auto_ptr

re: auto_ptr

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