fn groupAsync( userdata: ?*anyopaque, type_erased: *Io.Group, context: []const u8, context_alignment: Alignment, start: *const fn (context: *const anyopaque) void, ) void
fn groupAsync( userdata: ?*anyopaque, type_erased: *Io.Group, context: []const u8, context_alignment: Alignment, start: *const fn (context: *const anyopaque) void, ) void { const ev: *Evented = @ptrCast(@alignCast(userdata)); return groupConcurrent(ev, type_erased, context, context_alignment, start) catch { start(context.ptr); }; }