SpanResultingFromStructRef

FieldList.cs

using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Explicit)]
struct FieldList
{
    [FieldOffset(0)] private int _item0;
    [FieldOffset(4)] private int _item1;
    [FieldOffset(8)] private int _item2;
    [FieldOffset(12)] private int _item3;
    [FieldOffset(16)] private int _item4;
    [FieldOffset(20)] private int _item5;
    [FieldOffset(24)] private int _item6;
    [FieldOffset(28)] private int _item7;
    
    private void ShiftLocalsLeft_Switch(int startingAt)
    {
        switch (startingAt)
        {
            case 0: goto CASE0;
            case 1: goto CASE1;
            case 2: goto CASE2;
            case 3: goto CASE3;
            case 4: goto CASE4;
            case 5: goto CASE5;
            case 6: goto CASE6;
            case 7: goto CASE7;
        }
        goto END;                
        CASE0:_item0 = _item1;;
        CASE1:_item1 = _item2;
        CASE2:_item2 = _item3;
        CASE3:_item3 = _item4;
        CASE4:_item4 = _item5;
        CASE5:_item5 = _item6;
        CASE6:_item6 = _item7;
        CASE7:_item7 = default;
        END:;
    }
    
    private void ShiftLocalsLeft_SpanFor(int startingAt)
    {
        Span<int> valSpan = MemoryMarshal.CreateSpan(ref _item0, 8);
        for (var i = startingAt; i < 7; i++)
        {
            valSpan[i] = valSpan[i+1];
        }
    }
    private void ShiftLocalsLeft_SpanOperations(int startingAt)
    {
        Span<int> valSpan = MemoryMarshal.CreateSpan(ref _item0, 8);
        valSpan.Slice(startingAt).CopyTo(valSpan.Slice(startingAt - 1));
    }
}