Make NaiveDateTime::and_utc const

src/datetime/mod.rs

@@ -624,6 +624,14 @@ impl DateTime<Utc> {
         NaiveDateTime::from_timestamp_opt(secs, nsecs).as_ref().map(NaiveDateTime::and_utc)
     }
 
+    // FIXME: remove when our MSRV is 1.61+
+    // This method is used by `NaiveDateTime::and_utc` because `DateTime::from_naive_utc_and_offset`
+    // can't be made const yet.
+    // Trait bounds in const function / implementation blocks were not supported until 1.61.
+    pub(crate) const fn from_naive_utc(datetime: NaiveDateTime) -> Self {
+        DateTime { datetime, offset: Utc }
+    }
+
     /// The Unix Epoch, 1970-01-01 00:00:00 UTC.
     pub const UNIX_EPOCH: Self = Self { datetime: NaiveDateTime::UNIX_EPOCH, offset: Utc };
 }

src/naive/datetime/mod.rs

@@ -964,8 +964,9 @@ impl NaiveDateTime {
     /// assert_eq!(dt.timezone(), Utc);
     /// ```
     #[must_use]
-    pub fn and_utc(&self) -> DateTime<Utc> {
-        Utc.from_utc_datetime(self)
+    pub const fn and_utc(&self) -> DateTime<Utc> {
+        // FIXME: use `DateTime::from_naive_utc_and_offset` when our MSRV is 1.61+.
+        DateTime::from_naive_utc(*self)
     }
 
     /// The minimum possible `NaiveDateTime`.