+/** Compile the trie.
+ * A trie must be compiled before lookup is possible. Compiling the trie
+ * consists in building the tree.
+ *
+ * \param memlock if true, the trie is locked into the RAM (mlock).
+ *
+ * Usage of a trie:
+ * trie_insert(trie, ...);
+ * trie_insert(trie, ...);
+ * ...
+ * trie_insert(trie, ...);
+ *
+ * trie_compile(trie, lock);
+ *
+ * trie_lookup(trie, ...);
+ * trie_lookup(trie, ...);
+ */