Blog: Fun with references in C#

FunWithReferences.cs

using System;

ref struct RefStruct 
{
    public RefStruct(ref int i) => value = ref i;
    public ref int value;
}

partial class C
{
    public static RefStruct Instantiate(ref int  i) => new RefStruct(ref i);
    unsafe static RefStruct InstantiateAndLog(int v) 
    {
        Console.WriteLine($"{nameof(RefStruct)} created.");
        return Instantiate(ref v);
    }

    public static void M2(int v)
    {
        Console.WriteLine("---------M2----------");
        var rs = Instantiate(ref v);
        Dump(rs);
    }
    
    public static void M3(int v)
    {
        Console.WriteLine("---------M3----------");
        var rs = InstantiateAndLog(v);
        Dump(rs);
    }
    
    static void Dump(in RefStruct rs)
    {
        var bytes = BitConverter.GetBytes(rs.value);
        foreach(var b in bytes)
            Console.WriteLine($"{b,2:x}");
    }
    
    static void Main()
    {
        const int Value = 0x01020304;
        M2(Value);
        M3(Value);
    }    
}

Original idea:

using System;
partial class C
{
    public unsafe static Span<byte> CreateSpan(ref int  i)
    {
        return new Span<byte>(System.Runtime.CompilerServices.Unsafe.AsPointer(ref i), sizeof(int));
    } 
}

unsafe partial class C
{
    public static Span<byte> M(int i)
    {
        return CreateSpan(ref i);
    }
    
    public static void M2(int v)
    {
        var s = CreateSpan(ref v);
        Dump(s, "M2");
    }
    
    public static void M3(int v)
    {
        var s = M(v);
        Dump(s, "M3");
    }
    
    static void Dump(in Span<byte> span, string msg)
    {
        Console.WriteLine($"---------{msg}----------");
        for(var i = 0; i < span.Length; i++)
            Console.WriteLine($"{span[i],2:x}");
    }
    
    static void Main()
    {
        const int Value = 0x01020304;
        M2(Value);
        M3(Value);
    }    
}