3 replies to this topic

[irancplusplus]

Hi
what is most similar to this C++ code in C#:

int main()

{

	union

	{

		unsigned a;

		struct

		{

			unsigned short x;

			unsigned short y;

		};

	};

	a = 12345678;

	cout<< x;

        cout<< y;	

}

I looking for an equivalent code for union and struct in C#.

[gregwarner]

I googled this page off of MSDN's documentation site:
How to: Create a C/C++ Union Using Attributes (C#)

[lespauled]

C# doesn't have support for C/C++ unions. But, you can use StructLayout(LayoutKind.Explicit) and FieldOffset attributes to create equivalent functionality.

How to: Create a C/C++ Union Using Attributes (C#)

[kernelcoder]

Yes, so the equivalent code in C# will be like as follows....

[System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Explicit)]
struct TestUnion
{
    [System.Runtime.InteropServices.FieldOffset(0)]
    public uint a;

    [System.Runtime.InteropServices.FieldOffset(0)]
    public ushort x;

    [System.Runtime.InteropServices.FieldOffset(2)]
    public ushort y;
}

And here is the usage...

TestUnion uni = new TestUnion();
uni.x = 10;
uni.y = 1;

Can you guess what is the value of a? This is a homework for you: Tell me what is the value of a?