C++ -- Is there an implicit cast here from Fred* to auto_ptr<Fred>?
        Posted  
        
            by 
                q0987
            
        on Stack Overflow
        
        See other posts from Stack Overflow
        
            or by q0987
        
        
        
        Published on 2011-01-01T22:16:42Z
        Indexed on 
            2011/01/03
            16:54 UTC
        
        
        Read the original article
        Hit count: 437
        
Hello all,
I saw the following code,
#include <new>
#include <memory>
using namespace std;
class Fred;  // Forward declaration
typedef  auto_ptr<Fred>  FredPtr;
class Fred {
public:
  static FredPtr create(int i)
  { 
    return new Fred(i); // Is there an implicit casting here? If not, how can we return
                        // a Fred* with return value as FredPtr?
  }
private:
  Fred(int i=10)      : i_(i)    { }
  Fred(const Fred& x) : i_(x.i_) { }
  int i_;
};
Please see the question listed in function create.
Thank you
// Updated based on comments
Yes, the code cannot pass the VC8.0 error C2664: 'std::auto_ptr<_Ty>::auto_ptr(std::auto_ptr<_Ty> &) throw()' : cannot convert parameter 1 from 'Fred *' to 'std::auto_ptr<_Ty> &'
The code was copied from the C++ FAQ 12.15.
However, after making the following changes,
replace 
  return new Fred(i);
with
  return auto_ptr<Fred>(new Fred(i));
This code can pass the VC8.0 compiler. But I am not sure whether or not this is a correct fix.
© Stack Overflow or respective owner