CODEWITHSUNDEEP
c++mfc
Attilah
Attilah

Reputation: 17930

error using CArray

So, I am trying to use CArray like this : 

 CArray<CPerson,CPerson&> allPersons;
   int i=0;
   for(int i=0;i<10;i++)
   {
      allPersons.SetAtGrow(i,CPerson(i));
      i++;
   }

But when compiling my program, I get this error :

"error C2248: 'CObject::CObject' : cannot access private member declared in class 'CObject' c:\program files\microsoft visual studio 9.0\vc\atlmfc\include\afxtempl.h"

I don't even understand where this is coming from.

HELP!

Upvotes: 5

Views: 6858

Answers (6)

crashmstr
crashmstr

Reputation: 28573

The error you are getting is because you are trying to use a CArray as a return value from what I can gather. If you change it from returning a CArray to taking a reference parameter instead, that will compile.

Try this:

class CPerson
{
public:
    CPerson();
    CPerson(int i);
    void operator=(const CPerson& p) {}
private:
    char* m_strName;
};

CPerson::CPerson()
{}

CPerson::CPerson(int i)
{
    sprintf(m_strName,"%d",i);
}

void aFunction(CArray<CPerson,CPerson&> &allPersons)
{
    for(int i=0;i<10;i++)
    {
        allPersons.SetAtGrow(i,CPerson(i));
        i++;
    }
}

Upvotes: 8

Goldorak84
Goldorak84

Reputation: 3972

If CPerson is a complex object, maybe you should consider using pointers

   CArray<CPerson*,CPerson*> allPersons;
   int i=0;
   for(int i=0;i<10;i++)
      allPersons.SetAtGrow(i,new CPerson(i));

Don't forget to delete your array's content once it's not needed anymore

   for(int i=0;i<allPersons.GetSize();i++)
      delete allPersons.GetAt(i);

Upvotes: 0

IssamTP
IssamTP

Reputation: 2440

I'm not totally sure of what your problem was, but take also a look at this: Microsoft CObject derived class specifications.

You might want to add this code:

class Person
{
    // ...
    Person( const Person& src );
}

Person::Person( const Person& src ){ Person();*this = src; }

Hope it helps for the future.

Upvotes: 0

aJ.
aJ.

Reputation: 35450

Are you using any of the Copy constructor or assignment operator of CObject ? ( CArray is derived from CObject)

For instance:

 CArray<CPerson,CPerson&> allPersons;  

//do something

// This gives the error C2248, cannot access Copy constructor of CObject.
CArray<CPerson,CPerson&> aTemp = allPersons;

OR

Are you doing this?

CArray<CPerson,CPerson&> allPersons; 
...
CArray<CPerson,CPerson&> aTemp;

//Error, as Assignment operator is private
aTemp = allPersons;

EDIT: If you want to copy the elements in CArray, write a helper method CopyArray() and copy the elements manually.

CopyArray(sourceArray, DestArray&)
{
 for each element in SourceArray
 add the element to DestArray.
}

Upvotes: 2

mwigdahl
mwigdahl

Reputation: 16578

Is CPerson derived from CObject? Does it have a private constructor? Your use of SetAtGrow() seems correct to me otherwise.

If that doesn't work, you might try falling back to using the Add() function, as your loop doesn't seem to require SetAtGrow().

Upvotes: 0

Mark Ransom
Mark Ransom

Reputation: 308176

Do you mean to say CArray<CPerson> allPersons; ? I don't know how leaving out the contained type would lead to the reported error, but...

Upvotes: 0

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