LINQ Guarantees Ordering with SelectMany?

Question

I have an array of ordered enumerables IorderedEnumerable<T>[] foo and I want to flatten it so that the ordered enumerables of foo are concatenated together in the order they are stored in the array.

For example {{1, 2, 3}, {4, 5}, {6}} => {1, 2, 3, 4, 5, 6}

Can I do this by IOrderedEnumerable<T> bar = foo.SelectMany(x => x);, or does LINQ not guarantee how order is handled when flattening?

Answer 1

All LINQ to Objects methods (except, obviously, OrderBy() and ToDictionary()) will preserve source ordering.