From fa428913ef5bdb4d1e34902c60101ccea31e5f06 Mon Sep 17 00:00:00 2001
From: "Guilherme S. Salustiano" <guissalustiano@gmail.com>
Date: Sat, 13 Jul 2024 14:11:09 +0200
Subject: [PATCH] lower_inf

---
 diesel/src/pg/expression/functions.rs | 42 +++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/diesel/src/pg/expression/functions.rs b/diesel/src/pg/expression/functions.rs
index 246233d81bde..28404250a179 100644
--- a/diesel/src/pg/expression/functions.rs
+++ b/diesel/src/pg/expression/functions.rs
@@ -275,6 +275,48 @@ define_sql_function! {
     fn upper_inc<T: RangeHelper>(range: T) -> Bool;
 }
 
+define_sql_function! {
+    /// Returns if the range's lower bound inclusive.
+    /// # Example
+    ///
+    /// ```rust
+    /// # include!("../../doctest_setup.rs");
+    /// #
+    /// # table! {
+    /// #     posts {
+    /// #         id -> Integer,
+    /// #         versions -> Range<Integer>,
+    /// #     }
+    /// # }
+    /// #
+    /// # fn main() {
+    /// #     run_test().unwrap();
+    /// # }
+    /// #
+    /// # fn run_test() -> QueryResult<()> {
+    /// #     use self::posts::dsl::*;
+    /// #     use std::collections::Bound;
+    /// #     let conn = &mut establish_connection();
+    /// #     diesel::sql_query("DROP TABLE IF EXISTS posts").execute(conn).unwrap();
+    /// #     diesel::sql_query("CREATE TABLE posts (id SERIAL PRIMARY KEY, versions INT4RANGE NOT NULL)").execute(conn).unwrap();
+    /// #
+    /// use diesel::dsl::lower_inf;
+    /// diesel::insert_into(posts)
+    ///     .values(&[
+    ///        versions.eq((Bound::Included(5), Bound::Excluded(7))),
+    ///        versions.eq((Bound::Unbounded, Bound::Excluded(7))),
+    ///     ]).execute(conn)?;
+    ///
+    /// let cool_posts = posts.select(lower_inf(versions))
+    ///     .load::<bool>(conn)?;
+    /// assert_eq!(vec![false, true], cool_posts);
+    /// #     Ok(())
+    /// # }
+    /// ```
+    #[cfg(feature = "postgres_backend")]
+    fn lower_inf<T: RangeHelper>(range: T) -> Bool;
+}
+
 define_sql_function! {
     /// Returns range of integer.
     /// # Example