Requirements on types

For the first version:

• ForwardIterator is a model of Forward Iterator.

• LessThanComparable is a model of LessThan Comparable.

• The ordering on objects of type LessThanComparable is a strict weak ordering, as defined in the LessThan Comparable requirements.

• ForwardIterator's value type is the same type as LessThanComparable.

For the second version:

• ForwardIterator is a model of Forward Iterator.

• StrictWeakOrdering is a model of Strict Weak Ordering.

• ForwardIterator's value type is the same type as T.

• ForwardIterator's value type is convertible to StrictWeakOrdering's argument type.