Base Class Constructor parameter has a struct

Hi All,

I want to know if the following is possible.

Code:

---


struct MyStruct
{
 int x;
} ;

class AdvancedClass
{
  AdvancedClass( MyStruct myStruct ) ;
};

class BasicClass : public AdvancedClass
{
 BasicClass(void) ;
};

BasicClass::BasicClass(void) : AdvancedClass( {0} )  // doesnt compile
{

}

---

As you can see from this simple code the Advanced Base Class expects a MyStruct as a constructor parameter. The derived Basic class doesnt have any constructor paramets and tries to constuct an AdvancedClass with a MyStruct object that has an x value of 0.

The problem is that I dont know how to initialize a new MyStruct object inside the creation of the AdvancedClass object from the initialization list of the BasicClass object.

Any ideas?

Thanks

Try this.

Code:

---

BasicClass::BasicClass(void) : AdvancedClass( (MyStruct){0} )

---

It should work . . . Dinkumware doesn't mind it, and it's valid C99. (The cast, not the class stuff.)

Doesn't compile at all with VC++.
Alternatively, make MyStruct a class and make a constructor that takes an int.

Thanks for the reply mate,

I get the following error when i try it:

syntax error : missing ')' before '{'

If it makes any difference the MyStruct object is actually in the form of

Code:

---


strut MyStruct
{
 float x;
 float y;
 float z;
};

---

So the code is actually

Code:

---

BasicClass::BasicClass(void) : AdvancedClass( (MyStruct){0.0f,0.0f,0.0f} )

---

Sorry for the misleading example, the former one was quicker to type and i didnt think it would make a difference :)

Just put it into the constructor body. For POD types there is no loss from doing this. I doubt what dwks sais is valid C++. C++0x maybe, but new C99 features where never incorporated into C++.

Quote:

---

Doesn't compile at all with VC++.

---

Quote:

---

I doubt what dwks sai[d] is valid C++. C++0x maybe, but new C99 features [were] never incorporated into C++.

---

Hmm, you're right. Must be a GNU extension. Not surprising, really.

Quote:

---

Alternatively, make MyStruct a class and make a constructor that takes an int.

---

You can even do that for a structure. Structures (in C++, anyway) can have constructors, destructors, private and public labels, the whole works. In C++, the only difference between a struct and a class is that structs are public by default, and classes private.

thanks dwks i didnt know a structure could behave like that. It is compiling now :)

Thanks to the rest of you aswell