Error while using CList

[raochetan]

Can anyone tell me what is the problem in the following code. It gives me an error saying No Copy Constructor Available for MyStruct

In StdAfx.h:

struct MyStruct {
int x;
long y;
char z;
}

CList<MyStruct, MyStruct> MyList;


In the Main program:

MyStruct a;

a.x = 2;
a.y = 100000;
a.z= 'c';

MyList.AddTail( a );

How can one write a copy constructor for a structure.

 

[IonelBurtan]

The CList object needs this for its internal manipulation inside the AddTail method.

struct MyStruct {
int x;
long y;
char z;
MyStruct(MyStruct& ms)
{
x=ms.x;
y=ms.y;
z=ms.z;
}
MyStruct& operator=(MyStruct& ms)
{
x=ms.x;
y=ms.y;
z=ms.z;
return *this;
}
};

Hope this helps,
s-)

Blessed is he who in the name of justice and goodwill, sheperds the weak through the valley of darkness...

http://www20.brinkster.com/ionelb

 

[raochetan]

It worked.

Thaks a lot BurtanI.

 

[Zyrenthian]

That is really odd tho. It was my understanding that structs did not need a copy constructor. The reason for this was because a struct is only as large (sizeof) as its data members. I have tested this before by putting alot of functionality into a struct and if all i had in the struct for data was an int... the size of the struct would be 4.

I have never made a copy constructor for a struct and have always been able to:
MyStruct a,b;

a.x=1;
a.y = 2;
a.z = 3;

b = a; // this has never caused a problem.

Could someone post why we need a copy constructor with a struct. I am curious.

Matt

 

[IonelBurtan]

Yes Zyrentian, but you will not be able to:

MyList.AddTail( a );

Just &quot;step in&quot; in the debug mode in the AddTail event to see how it works and you will have a better grasp of the issue.

Hope this helps, s-)

Blessed is he who in the name of justice and goodwill, sheperds the weak through the valley of darkness...

http://www20.brinkster.com/ionelb

 

[Zyrenthian]

Thanx!