C# 7.2 Reinterpret cast in safe code

Posted

C#, Performance

Reinterpret cast in C# code

Reinterpret cast with Span

Did you know you can do a reinterpret cast in C# where we treat a array of structs as a array of bytes?

static unsafe void Main(string[] args)
{
    var colorArray = new RGBA[]
    {
        new RGBA(1,2,3,4),
        new RGBA(9,8,7,6)
    };
    fixed (RGBA* ptr = colorArray)
    {
        byte* bytes = (byte*)ptr;
        var byteSize = colorArray.Length * 4;
        for (int i = 0; i < byteSize; i++)
        {
            Console.WriteLine(bytes[i]);
        }
    }
    Console.ReadKey();
}

Did you know the above code is now possible in safe code with the help of Span and C# 7.2?

static void Main(string[] args)
{
    var colorArray = new RGBA[]
    {
        new RGBA(1,2,3,4),
        new RGBA(9,8,7,6)
    };
    Span<byte> bytes = MemoryMarshal.AsBytes(colorArray.AsSpan());
    for (int i = 0; i < bytes.Length; i++)
    {
        Console.WriteLine(bytes[i]);
    }
    Console.ReadKey();
}

Enjoy but do use with care :)