VB -> C#: Dropping a bit in a bitwise operation

[Thieum]

Input code

Module Module1


    <Flags()>
    Public Enum FillType
        All = &H1
        Latest = &H2
        Clean = &H4
        Recursive = &H8
        Append = &H10
        CleanAndLatest = Clean Or Latest
    End Enum
    Sub Main()
        Dim test1 = Test(FillType.All)
        Console.WriteLine("FillType.All -> " & test1)
        Dim test2 = Test(FillType.Latest)
        Console.WriteLine("FillType.Latest -> " & test2)
        Dim test3 = Test(FillType.Recursive)
        Console.WriteLine("FillType.Recursive -> " & test3)
        Dim test4 = Test(FillType.Append)
        Console.WriteLine("FillType.Append -> " & test4)
        Dim test5 = Test(FillType.CleanAndLatest)
        Console.WriteLine("FillType.CleanAndLatest -> " & test5)
        Dim test6 = Test(FillType.All Or FillType.Recursive)
        Console.WriteLine("FillType.All Or FillType.Recursive -> " & test6)

        Console.ReadLine()
    End Sub

    Function Test(options As FillType) As Object
        Dim opts As Object
        If (options And Not FillType.Recursive) = 0 Then
            opts = FillType.All
        Else
            opts = options And Not FillType.Recursive
        End If
        Return opts
    End Function

End Module

Erroneous output

using System;
using Microsoft.VisualBasic.CompilerServices;

namespace ConsoleApp4
{
    static class Module1
    {
        [Flags()]
        public enum FillType
        {
            All = 0x1,
            Latest = 0x2,
            Clean = 0x4,
            Recursive = 0x8,
            Append = 0x10,
            CleanAndLatest = Clean | Latest
        }

        public static void Main()
        {
            var test1 = Test(FillType.All);
            Console.WriteLine(Operators.ConcatenateObject("FillType.All -> ", test1));
            var test2 = Test(FillType.Latest);
            Console.WriteLine(Operators.ConcatenateObject("FillType.Latest -> ", test2));
            var test3 = Test(FillType.Recursive);
            Console.WriteLine(Operators.ConcatenateObject("FillType.Recursive -> ", test3));
            var test4 = Test(FillType.Append);
            Console.WriteLine(Operators.ConcatenateObject("FillType.Append -> ", test4));
            var test5 = Test(FillType.CleanAndLatest);
            Console.WriteLine(Operators.ConcatenateObject("FillType.CleanAndLatest -> ", test5));
            var test6 = Test(FillType.All | FillType.Recursive);
            Console.WriteLine(Operators.ConcatenateObject("FillType.All Or FillType.Recursive -> ", test6));
            Console.ReadLine();
        }

        public static object Test(FillType options)
        {
            object opts;
            if ((int)(options & !FillType.Recursive) == 0)
            {
                opts = FillType.All;
            }
            else
            {
                opts = options & !FillType.Recursive;
            }

            return opts;
        }
    }
}

Expected output

using System;
using Microsoft.VisualBasic.CompilerServices;

namespace ConsoleApp4
{
    static class Module1
    {
        [Flags()]
        public enum FillType
        {
            All = 0x1,
            Latest = 0x2,
            Clean = 0x4,
            Recursive = 0x8,
            Append = 0x10,
            CleanAndLatest = Clean | Latest
        }

        public static void Main()
        {
            var test1 = Test(FillType.All);
            Console.WriteLine(Operators.ConcatenateObject("FillType.All -> ", test1));
            var test2 = Test(FillType.Latest);
            Console.WriteLine(Operators.ConcatenateObject("FillType.Latest -> ", test2));
            var test3 = Test(FillType.Recursive);
            Console.WriteLine(Operators.ConcatenateObject("FillType.Recursive -> ", test3));
            var test4 = Test(FillType.Append);
            Console.WriteLine(Operators.ConcatenateObject("FillType.Append -> ", test4));
            var test5 = Test(FillType.CleanAndLatest);
            Console.WriteLine(Operators.ConcatenateObject("FillType.CleanAndLatest -> ", test5));
            var test6 = Test(FillType.All | FillType.Recursive);
            Console.WriteLine(Operators.ConcatenateObject("FillType.All Or FillType.Recursive -> ", test6));
            Console.ReadLine();
        }

        public static object Test(FillType options)
        {
            object opts;
            if ((int)(options & ~FillType.Recursive) == 0)
            {
                opts = FillType.All;
            }
            else
            {
                opts = options & ~FillType.Recursive;
            }

            return opts;
        }
    }
}

Details

• VS Extension v81.6.0

Dropping a bit with bitwise operator in VB.NET is done with a combination of AND and NOT :

https://stackoverflow.com/a/38201868/444469

whereas in C# it's done with & and the complement operator ~ :

https://stackoverflow.com/a/4778181/444469

[GrahamTheCoder]

Thanks for the full example and explanation. Should be a straightforward adjustment to convert Not into ~ for numeric types

[GrahamTheCoder]

I believe this is fixed in e596227