Hello,
if i wanted to access the elements of an array which is owned by an
auto_ptr, as:
#include <memory>
int main(){
std::auto_ptr<i nt> p(new int[10]);
p[2]=2; //Error: no operator[] defined
return 0;
}
would the best way be:
#include <memory>
int main(){
std::auto_ptr<i nt> p(new int[10]);
int *p_;
p_=p.get();
p_[2]=2;
return 0;
}
I thought deriving a class from auto_ptr, but the pointer member is
protected and subject to have different names on different C++ standard
library implementations .
TIA, 6 1522
Azdo wrote: Hello,
if i wanted to access the elements of an array which is owned by an auto_ptr, as:
you should not use std::auto_ptr<> for arrays as in its destuctor it
'delete' owned pointer (and you dont want it to 'delete' memory that was
acquired with 'new[]') #include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); p[2]=2; //Error: no operator[] defined return 0; }
would the best way be:
#include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); int *p_; p_=p.get(); p_[2]=2;
return 0; }
I thought deriving a class from auto_ptr, but the pointer member is protected and subject to have different names on different C++ standard library implementations .
TIA,
Kyle wrote: Azdo wrote: Hello,
if i wanted to access the elements of an array which is owned by an auto_ptr, as:
you should not use std::auto_ptr<> for arrays as in its destuctor it 'delete' owned pointer (and you dont want it to 'delete' memory that was acquired with 'new[]')
#include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); p[2]=2; //Error: no operator[] defined return 0; }
would the best way be:
#include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); int *p_; p_=p.get(); p_[2]=2;
return 0; }
I thought deriving a class from auto_ptr, but the pointer member is protected and subject to have different names on different C++ standard library implementations .
TIA,
I think you can use auto_ptr on individual elements of array.
Azdo wrote: Hello,
if i wanted to access the elements of an array which is owned by an auto_ptr, as:
#include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); p[2]=2; //Error: no operator[] defined return 0; }
would the best way be:
#include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); int *p_; p_=p.get(); p_[2]=2;
return 0; }
I thought deriving a class from auto_ptr, but the pointer member is protected and subject to have different names on different C++ standard library implementations .
TIA,
Hm, I doubt that it is a good idea to use std::auto_ptr to hold an array:
Somewhere inside the auto_ptr object there ought to be a pointer int* ptr.
At initialisation, you set ptr = new int [10]. However, upon destruction of
the auto_ptr object, memory shall be released, and I bet you, the
destructor will say: delete ptr. Note that it does not say: delete[] ptr.
Thus, in your code, new[] and delete will not match.
I think, you could define your own auto_array_ptr code quickly, or look for
some library. I would guess this has been done before. Such an
auto_array_ptr class would define operator[].
Best
Kai-Uwe Bux
vindhya wrote: Kyle wrote: Azdo wrote: > Hello, > > if i wanted to access the elements of an array which is owned by an > auto_ptr, as:
you should not use std::auto_ptr<> for arrays as in its destuctor it 'delete' owned pointer (and you dont want it to 'delete' memory that was acquired with 'new[]')
> > #include <memory> > > int main(){ > std::auto_ptr<i nt> p(new int[10]); > p[2]=2; //Error: no operator[] defined > return 0; > } > > would the best way be: > > #include <memory> > > int main(){ > std::auto_ptr<i nt> p(new int[10]); > int *p_; > p_=p.get(); > p_[2]=2; > > return 0; > } > > I thought deriving a class from auto_ptr, but the pointer member is > protected and subject to have different names on different C++ standard > library implementations . > > TIA, >
I think you can use auto_ptr on individual elements of array.
Oh, I think I didn't notice the array issue at all! That's why the []
operator is not defined...
Thanks Kai, Kyle, vindhya!
Hi,
<skip> I think you can use auto_ptr on individual elements of array.
Oh, I think I didn't notice the array issue at all! That's why the [] operator is not defined...
Try boost::smart_pt r lib at www.boost.org
--
Serge
Azdo wrote: Hello,
if i wanted to access the elements of an array which is owned by an auto_ptr, as:
#include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); p[2]=2; //Error: no operator[] defined return 0; }
would the best way be:
#include <memory>
int main(){ std::auto_ptr<i nt> p(new int[10]); int *p_; p_=p.get(); p_[2]=2;
return 0; }
I thought deriving a class from auto_ptr, but the pointer member is protected and subject to have different names on different C++ standard library implementations .
TIA,
use a std::vector or another container for collections of values.
possibly use std::auto_ptr<s td::vector<int> > however, if that's for
"optimizati on" purposes, you're probably better off just avoiding
copying the container (eg, pass by reference). This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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