[ACCEPTED]-C# StructLayout.Explicit Question-structlayout

Accepted answer

Score: 12

The common language runtime contains a verifier 15 that makes sure the running code (verifiable 14 IL) cannot possibly corrupt memory in the 13 managed environment. This prevents you to 12 declare such a structure in which fields 11 overlap. Basically, your struct contains 10 two data members. One integer (which is 9 4 bytes) and a native integer (pointer size). On 8 a 32 bit CLR, in which you are probably 7 running your code, the char[] will take 4 bytes 6 so if you put the integer less than four 5 bytes away from the beginning of the struct, you'll 4 have overlapping fields. It's interesting 3 to note that both of your code snippets 2 with fail on a 64 bit runtime, as the pointer 1 size is 8 bytes.

Score: 1

I figured I'd respond with the solution 5 I used to create the union -- which was 4 my original intention. I used an unsafe 3 struct and a fixed array and then used a 2 property to interact with the fixed array. I 1 believe this should do what I want.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;

namespace StructTest
{

    [StructLayout(LayoutKind.Explicit)]
    unsafe struct OuterType
    {
        private const int BUFFER_SIZE = 100;

        [FieldOffset(0)]
        private int transactionType;

        [FieldOffset(0)]
        private fixed byte writeBuffer[BUFFER_SIZE];

        public int TransactionType
        {
            get { return transactionType; }
            set { transactionType = value; }
        }

        public char[] WriteBuffer
        {
            set
            {
                char[] newBuffer = value;

                fixed (byte* b = writeBuffer)
                {
                    byte* bptr = b;
                    for (int i = 0; i < newBuffer.Length; i++)
                    {
                         *bptr++ = (byte) newBuffer[i];
                    }
                }
            }

            get
            {
                char[] newBuffer = new char[BUFFER_SIZE];

                fixed (byte* b = writeBuffer)
                {
                    byte* bptr = b;
                    for (int i = 0; i < newBuffer.Length; i++)
                    {
                        newBuffer[i] = (char) *bptr++;
                    }
                }

                return newBuffer;
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            OuterType t = new OuterType();
            System.Console.WriteLine(t);
        }
    }
}

Source: stackoverflow.com

[ACCEPTED]-C# StructLayout.Explicit Question-structlayout

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