Basic C++ doubt

[munna]

It might be a very silly doubt, but please bear with me.

Now let us consider the following code.

class Fred {
 public:
   static FredPtr create();
   static FredPtr create(int i, int j);
   ...
 private:
   Fred();
   Fred(int i, int j);
   ...
 };
 
 class FredPtr { /* ... */ };//the code above.
 
 inline FredPtr Fred::create()             { return new Fred(); }//Isn't the return type wrong ?
 inline FredPtr Fred::create(int i, int j) { return new Fred(i,j); }

class Fred {
 public:
   static FredPtr create();
   static FredPtr create(int i, int j);
   ...
 private:
   Fred();
   Fred(int i, int j);
   ...
 };
 
 class FredPtr { /* ... */ };//the code above.
 
 inline FredPtr Fred::create()             { return new Fred(); }//Isn't the return type wrong ?
 inline FredPtr Fred::create(int i, int j) { return new Fred(i,j); }

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and the code here

FredPtr ptr1(Fred::create());
FredPtr ptr2 = ptr1;//What will happen here ?

FredPtr ptr1(Fred::create());
FredPtr ptr2 = ptr1;//What will happen here ?

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Can you please explain how count will change in this case ?

Another doubt

Fred* const old = p_; means old is a const pointer to a const Fred. Then how can it be changed in the statement "if (--old->count_ == 0)" ?

Thanks a lot.

[jacek]

inline FredPtr Fred::create() { return new Fred(); }//Isn't the return type wrong ?

No, because there's FredPtr::FredPtr(Fred* p) constructor[1] that will be used to convert Fred* to FredPtr.

FredPtr ptr1(Fred::create());
FredPtr ptr2 = ptr1;//What will happen here ?

Both FredPtrs will point to the same Fred object and the reference count will be 2.

Fred* const old = p_; means old is a const pointer to a const Fred.

No, it's a constant pointer to a non-constant object.

[1] and it doesn't have "explicit" keyword in front of it.

[wysota]

I think it's also worth to note that in this situation:

FredPtr ptr2 = ptr1;

FredPtr ptr2 = ptr1;

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the compiler will use a copy constructor (line 20 of the listing in the first post) and not the assignment operator (lines 21-32 of the same listing).