Question

i have this code function in C++ to convert different objects to bytes array:

template <typename T>
static void GetBytesArrayFrom(T value, BYTE *out_array)
{
    union BytesConverter
    {
        T value;
        BYTE bytes_array[sizeof(T)];
    };

    BytesConverter bc;
    bc.value = value;

    memcpy(out_array, bc.bytes_array, sizeof(T));
}

now i am trying to make same function in C#, but have a problem:

public void GetBytesFrom<T>(T value, byte[] out_array) where T : object
{
    struct BytesConverter
    {
        [FieldOffset(0)] 
        T value; //T is unknown here
        [FieldOffset(0)] 
        byte[] bytes_array = new byte[sizeof(T)]; //and here
    }

int test = 0;
}

and it appear to be i can’t define struct inside function at all.
How then it possible to do same cool conversion function in C#?

Answer 1

static void GetBytes<T>(T obj, byte[] data)
{
    unsafe
    {
        fixed (byte* pData = data)
        {
            Marshal.StructureToPtr(obj, (IntPtr)pData, false /*careful...*/);
        }
    }
}