Drop netstandard2.0

[Zetanova]

Any plans to drop the netstandard2.0 support?

I want/wanted to add an improved version of cursor.PutMultiple the current impl. has not a nice surface.
and then discovered that the projects still targets netstandard2.0, this is only required for .NET Framework 4.6.1+ (legacy Windows apps)
Because Lightning.Net seams stable legacy users could still use an older version of the package.

Benefits of dropping netstandard2.0: (AI generated)

• Performance - LibraryImport (source-generated P/Invoke) vs DllImport - faster marshalling
• Modern APIs - Span improvements, MemoryMarshal additions, better Unsafe class
• Language features - ref readonly, file scoped types, required members, init properties
• Generic math - IBinaryInteger, IUnsignedNumber - exactly what you're using
• Maintenance - Single code path, no #if conditionals, simpler CI
• AOT/Trimming - Full Native AOT support, better trimming

[CoreyKaylor]

I would look a little closer. Many of those items are already in the current version while maintaining netstandard2.0 which has a little broader purpose beyond 4.6.1+ (legacy apps) as you stated. If you want something nicer for PutMultiple, make your suggestion and keep the discussion focused to that and not on irrelevant other items that aren't accurate.

[Zetanova]

Many packages drop there support already.
As example, this is the PutMultiple in the latest c# version,
I think it should work from dotnet 8, but for sure not in netstandard2.0

Yes, LibraryImport seams to work and is already used by this project,

I will simply make the PR

Example:

public static partial class LightningCursorExtensions
{
    [StructLayout(LayoutKind.Sequential)]
    private readonly struct MDBVal(nint size, nint ptr)
    {
        public readonly nint size = size;
        public readonly nint ptr = ptr;
    }

    [LibraryImport("lmdb")]
    [UnmanagedCallConv(CallConvs = [typeof(CallConvCdecl)])]
    private static partial int mdb_cursor_put(nint cursor, in MDBVal key, in MDBVal data, uint flags);


    [UnsafeAccessor(UnsafeAccessorKind.Field, Name = "_handle")]
    private static extern ref nint GetHandle(LightningCursor cursor);

    private static nint AsPointer(ReadOnlySpan<byte> span) => AsPointer(in MemoryMarshal.GetReference(span));

    private static unsafe nint AsPointer(ref readonly byte data) => (nint)Unsafe.AsPointer(in data);

    public static MDBResultCode PutMultiple<T>(this LightningCursor cursor, ReadOnlySpan<byte> key, ReadOnlySpan<T> values)
        where T : unmanaged
    {
        if (values.IsEmpty)
            return MDBResultCode.Success;

        var valuesBytes = MemoryMarshal.AsBytes(values);

        var mdbKey = new MDBVal(key.Length, AsPointer(key));

        Span<MDBVal> dataBuffer =
        [
            new (Unsafe.SizeOf<T>(), AsPointer(valuesBytes)),
            new (values.Length, nint.Zero)
        ];

        var result = mdb_cursor_put(GetHandle(cursor), in mdbKey, in dataBuffer[0], (uint)CursorPutOptions.MultipleData);

        return (MDBResultCode)result;
    }
}

[Zetanova]

I added the #199

Yes, the new features seams to work/compile to netstandard2.0

My code example of the previous comment has even bugs AsPointer(valuesBytes) will not work because it is not pinned.

[CoreyKaylor]

Yes, I was going to mention I like the PR code better. 😄

[Zetanova]

This is the AI slop, first u need to convince the agent to make the right thing with 3-4 prompts
and it in between to convince you to put some bugs into your code.