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Object instance creation error

Ami
Hi All,
I am trying to create a class whose constructor takes Void
parameter and stores it for future reference. It works fine as
expected.

class base
{
public:
base(LPVOID pObj){ //store lpvoid for reference};
virtual ~base(){};
virtual void func1() { printf("Hello from base\n") };
};

When I create another class from above given class and try to create
object from it, it get following error.

error C2664: 'derived::derived' : cannot convert parameter 1 from
'const int' to 'const class derived &'
Reason: cannot convert from 'const int' to 'const class
derived'
No constructor could take the source type, or constructor
overload resolution was ambiguous
class derived:public base
{
protected:
virtual void func1(){ printf("Hello from Derived\n") };
};

int main()
{
base *nderived= new derived(NULL); //error
}
Please can any one help me to make this working.
Thanks and Regards

Aug 21 '07 #1
5 1792
On Tue, 21 Aug 2007 04:14:31 -0700, Ami wrote:
Hi All,
I am trying to create a class whose constructor takes Void
parameter and stores it for future reference. It works fine as
expected.

class base
{
public:
base(LPVOID pObj){ //store lpvoid for reference};
virtual ~base(){};
virtual void func1() { printf("Hello from base\n") };
};

When I create another class from above given class and try to create
object from it, it get following error.

error C2664: 'derived::derived' : cannot convert parameter 1 from
'const int' to 'const class derived &'
Reason: cannot convert from 'const int' to 'const class
derived'
No constructor could take the source type, or constructor
overload resolution was ambiguous
class derived:public base
{
protected:
virtual void func1(){ printf("Hello from Derived\n") };
public:
derived(LPVOID v) : base(v) {}
};

int main()
{
base *nderived= new derived(NULL); //error
}
Please can any one help me to make this working.
Thanks and Regards
--
Obnoxious User
Aug 21 '07 #2
On Aug 21, 4:14 pm, Ami <ver_amit...@yahoo.comwrote:
Hi All,
I am trying to create a class whose constructor takes Void
parameter and stores it for future reference. It works fine as
expected.

class base
{
public:
base(LPVOID pObj){ //store lpvoid for reference};
virtual ~base(){};
virtual void func1() { printf("Hello from base\n") };

};

When I create another class from above given class and try to create
object from it, it get following error.

error C2664: 'derived::derived' : cannot convert parameter 1 from
'const int' to 'const class derived &'
Reason: cannot convert from 'const int' to 'const class
derived'
No constructor could take the source type, or constructor
overload resolution was ambiguous

class derived:public base
{
protected:
virtual void func1(){ printf("Hello from Derived\n") };

};

int main()
{
base *nderived= new derived(NULL); //error

}

Please can any one help me to make this working.
Thanks and Regards
Since the base class constrcutor needs a argument, you derived class'
constructor should provide it.
class derived : public base
{
derived(void*):base(NULL){}
}

would make your code compile..

Best Regards,
Senthil

Aug 21 '07 #3
On 8/21/2007 1:14 PM, Ami wrote:
Hi All,
I am trying to create a class whose constructor takes Void
parameter and stores it for future reference. It works fine as
expected.

class base
{
public:
base(LPVOID pObj){ //store lpvoid for reference};
virtual ~base(){};
virtual void func1() { printf("Hello from base\n") };
};

When I create another class from above given class and try to create
object from it, it get following error.

error C2664: 'derived::derived' : cannot convert parameter 1 from
'const int' to 'const class derived &'
Reason: cannot convert from 'const int' to 'const class
derived'
No constructor could take the source type, or constructor
overload resolution was ambiguous
class derived:public base
{
protected:
virtual void func1(){ printf("Hello from Derived\n") };
};

int main()
{
base *nderived= new derived(NULL); //error
}
Please can any one help me to make this working.
Thanks and Regards
derived does not have a c'tor that's able to take 'NULL'.
You have to declare that c'tor in class derived.

Regards,
Stefan

--
Stefan Naewe stefan dot naewe at atlas-elektronik dot com
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please http://www.expita.com/nomime.html
Aug 21 '07 #4
Ami
On Aug 21, 4:16 pm, Obnoxious User <O...@127.0.0.1wrote:
On Tue, 21 Aug 2007 04:14:31 -0700, Ami wrote:
Hi All,
I am trying to create a class whose constructor takes Void
parameter and stores it for future reference. It works fine as
expected.
class base
{
public:
base(LPVOID pObj){ //store lpvoid for reference};
virtual ~base(){};
virtual void func1() { printf("Hello from base\n") };
};
When I create another class from above given class and try to create
object from it, it get following error.
error C2664: 'derived::derived' : cannot convert parameter 1 from
'const int' to 'const class derived &'
Reason: cannot convert from 'const int' to 'const class
derived'
No constructor could take the source type, or constructor
overload resolution was ambiguous
class derived:public base
{
protected:
virtual void func1(){ printf("Hello from Derived\n") };

public:
derived(LPVOID v) : base(v) {}
};
int main()
{
base *nderived= new derived(NULL); //error
}
Please can any one help me to make this working.
Thanks and Regards

--
Obnoxious User
Hi Obnoxious,
Many thanks for reply. It works as expected. Thanks again.
Regards

Aug 21 '07 #5
Ami
On Aug 21, 4:57 pm, Ami <ver_amit...@yahoo.comwrote:
On Aug 21, 4:16 pm, Obnoxious User <O...@127.0.0.1wrote:
On Tue, 21 Aug 2007 04:14:31 -0700, Ami wrote:
Hi All,
I am trying to create a class whose constructor takes Void
parameter and stores it for future reference. It works fine as
expected.
class base
{
public:
base(LPVOID pObj){ //store lpvoid for reference};
virtual ~base(){};
virtual void func1() { printf("Hello from base\n") };
};
When I create another class from above given class and try to create
object from it, it get following error.
error C2664: 'derived::derived' : cannot convert parameter 1 from
'const int' to 'const class derived &'
Reason: cannot convert from 'const int' to 'const class
derived'
No constructor could take the source type, or constructor
overload resolution was ambiguous
class derived:public base
{
protected:
virtual void func1(){ printf("Hello from Derived\n") };
public:
derived(LPVOID v) : base(v) {}
};
int main()
{
base *nderived= new derived(NULL); //error
}
Please can any one help me to make this working.
Thanks and Regards
--
Obnoxious User

Hi Obnoxious,
Many thanks for reply. It works as expected. Thanks again.
Regards
Many thanks all of you for suggestion.
Regards,

Aug 21 '07 #6

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