+/**
+ * GtkTreeViewColumnDropFunc:
+ * @tree_view: A #GtkTreeView
+ * @column: The #GtkTreeViewColumn being dragged
+ * @prev_column: A #GtkTreeViewColumn on one side of @column
+ * @next_column: A #GtkTreeViewColumn on the other side of @column
+ * @data: (closure): user data
+ *
+ * Function type for determining whether @column can be dropped in a
+ * particular spot (as determined by @prev_column and @next_column). In
+ * left to right locales, @prev_column is on the left of the potential drop
+ * spot, and @next_column is on the right. In right to left mode, this is
+ * reversed. This function should return %TRUE if the spot is a valid drop
+ * spot. Please note that returning %TRUE does not actually indicate that
+ * the column drop was made, but is meant only to indicate a possible drop
+ * spot to the user.
+ *
+ * Returns: %TRUE, if @column can be dropped in this spot
+ */