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C++/CLI -- address of operator

Consider this code in Managed Extensions for C++ (.Net 1.1)

int MyInt;

MyFunction(&MyInt);

That calls MyFunction with the address of MyInt, because MyFunction wants an int*.

Now, in .Net 2+, MyFunction wants an int^.

So ... how do I call it? If I say
MyFunction(%MyInt);
I am told Error C3071: % can only be applied to an instance of a ref class or a value type.

I would have thought that int was a value type.

So again, how do I call MyFunction?

Thanks!

SOLUTION

jkr

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Daniel Wilson

ASKER

yes, % is modulus.

And in real C++, it has no other meaning, to my knowledge.

But in C++/CLI it is similar to &. See the "tracking reference" section here:
http://en.wikipedia.org/wiki/C%2B%2B/CLI

SOLUTION

mrjoltcola

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tculler

I think what the function wants is a handle to an Int32^. I may be wrong, but the following demonstration should be along the lines you're looking for:

System::Int32 someInt;
 
MyFunction(%someInt);

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Daniel Wilson

ASKER

MyFunction(^%MyInt);
does not compile. In addition to C3071, I get:
C2100: Illegal indirection
C3192: Syntax Error: '^' is not a prefix operator. (Did you mean '*' ?)

Daniel Wilson

ASKER

System::Int32 someInt;

MyFunction(%someInt);

This doesn't compile either. I still get C3071.

Thanks to both of you for your ideas. Do you have more I can try?

Daniel Wilson

ASKER

Another overload out there for MyFunction is
static void MyFunction(System::IntPtr x);

I do find that the call MyFunction(MyInt); compiles. Will I be sorry if I go with this?

SOLUTION

tculler

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Daniel Wilson

ASKER

>>Well, have you tried just using the address-of operator?

& ? Yes, I started there. But I get C2665: 'MyFunction': none of the X overloads could convert all the argument types

Of course, MyFunction is not really mine. I'm working against the Tao Framework which is written in C#.

One of the functions is this one, the 2nd parameter being my problem one:
public static extern int ChoosePixelFormat(IntPtr deviceContext, ref PIXELFORMATDESCRIPTOR pixelFormatDescriptor);

Another is this, again the 2nd parameter being the one in question.
public static
void glGenTextures(Int32 n, [Out] IntPtr textures)

ASKER CERTIFIED SOLUTION

Daniel Wilson

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