Adds support for the ltree PostgreSQL extension type to Diesel, supporting all functions and operators thereon.
Binary protocol support for Ltrees (has been committed)[https://commitfest.postgresql.org/24/2242/], but not released as of 2020.04.29. As such, the only option for Diesel, which uses the Postgres binary protocol (likewise for rust_postgres), is to treat the transmittion of Ltrees as Postgres text, until this commit goes live. This crate currently transmits Ltree paths as text, then casts them to ltree.
Until binary protocol support is added for Ltrees, you need to select ltree2text(my_tree).