Initializes @iter with the first iterator in the tree (the one at the path "0") and returns %TRUE. Returns %FALSE if the tree is empty.
the uninitialized #GtkTreeIter-struct
Return: %TRUE, if @iter was set
See Implementation
Initializes @iter with the first iterator in the tree (the one at the path "0") and returns %TRUE. Returns %FALSE if the tree is empty.