PP$-11\mathrm{.}04$: Family$-$tree

In order to represent the interconnected$-$ness of data, it is often important to have pointers

within a struct, either pointing to data of a different type or potentially pointing to the same

struct type. In the latter case, the syntax can be a bit awkward, as we have to create the

pointer before we have fully defined the struct itself!

Consider the following struct definition, which could be a useful way of representing a family

relationship:

Here we have defined a struct named person, that includes, as part of its definition,

pointers to other person variables representing a mother and father, respectively. With

this syntax, we have to be careful whether we are accessing a variable of the struct type or a

pointer to a variable of the struct type, as the following example illustrates: