Question

I have some code that creates a list of lists. The list is of this type:

 List<List<Device>> GroupedDeviceList = new List<List<Device>>();

But need to return the result in the following type:

 IEnumerable<IGrouping<object, Device>>

Is this possible via a cast etc or should I be using a different definition for my list of lists?

Answer 1

If I understood your intentions correctly, the answer is below:

    var result = GroupedDeviceList
        .SelectMany(lst => lst.GroupBy(device => (object)lst));

result is of type IEnumerable<IGrouping<object, Device>>, where object is a reference to your List<Device>.