Function serialize_iterator 

pub fn serialize_iterator<I, T, Output>(
    iter: &mut I,
    context: &mut SerializationContext<Output>,
) -> Result<(), Error>
where
    I: Iterator<Item = T>,
    T: BinarySerializer,
    Output: BinaryOutput,

Helper function for implementing serialization of any iterable data source, keeping a format which is compatible with both known and unknown sized iterables, allowing replacing data structures without breaking the serialization format.

All the built-in BinarySerializer implementations for iterables use this function (or at least the same binary format).