Hi, While reading our documentation about pseudo-types [1] I noticed that it says:
""" anyelement - Indicates that a function accepts any data type anyarray - Indicates that a function accepts any array data type """ This may give an impression that anyelement and anyarray can be used as an argument ("accepted") but not as a return value, while in fact they can. In particular we have [2]: """ array_fill(anyelement, integer[] [, integer[] ] ) -> anyarray unnest(anyarray) -> setof anyelement """ What makes section 8.21 even more confusing is the fact that a little below we say: """ cstring - Indicates that a function accepts or *returns* a null-terminated C string """ Should we be slightly more precise here? [1]: https://www.postgresql.org/docs/current/datatype-pseudo.html [2]: https://www.postgresql.org/docs/current/functions-array.html -- Best regards, Aleksander Alekseev