Unfortunately the compiler used for Unity 3D does not support Tuples. Tuples are a convenient way to lump a couple of types together into one object without creating a class.
So, if like me you needed a list to contain a string and a float for one entry, you could do so like this:
public List<Tuple<string,float>> things;
Then you could access the parts of the item, add both parts at the same time, etc.
There are a bunch of class definitions available that will let you use something very similar to Tuple in Unity. I didn’t want to go to that effort, so I ended up with using an ArrayList. This will hold multiple objects of different types in a nice ordered array.
public List<ArrayList> things;
Now each item in the list is an array and I can get at the contents using normal array syntax.
ArrayList thing = things;
label.text = thing as string;
duration = (float)thing;
There’s no error checking here, but you get the basic idea.