From 0c011dea8b3f9b5aad42a685b8b971f60a46be7b Mon Sep 17 00:00:00 2001
From: LingMan <LingMan@users.noreply.github.com>
Date: Fri, 21 Apr 2023 23:09:51 +0200
Subject: [PATCH] Mark `SecondsFormat` as #[non_exhaustive]

Removes the current hack and replaces it with the proper attribute that's available since Rust 1.45.

Co-developed-by: TennyZhuang <zty0826@gmail.com>
---
 src/datetime/mod.rs   | 8 +-------
 src/datetime/tests.rs | 8 --------
 2 files changed, 1 insertion(+), 15 deletions(-)

diff --git a/src/datetime/mod.rs b/src/datetime/mod.rs
index 8f84ab1b..abe623bb 100644
--- a/src/datetime/mod.rs
+++ b/src/datetime/mod.rs
@@ -47,6 +47,7 @@ mod tests;
 /// future, so exhaustive matching in external code is not recommended.
 ///
 /// See the `TimeZone::to_rfc3339_opts` function for usage.
+#[non_exhaustive]
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
 pub enum SecondsFormat {
     /// Format whole seconds only, with no decimal point nor subseconds.
@@ -68,10 +69,6 @@ pub enum SecondsFormat {
     /// display all available non-zero sub-second digits.  This corresponds to
     /// [Fixed::Nanosecond](format/enum.Fixed.html#variant.Nanosecond).
     AutoSi,
-
-    // Do not match against this.
-    #[doc(hidden)]
-    __NonExhaustive,
 }
 
 /// ISO 8601 combined date and time with time zone.
@@ -699,8 +696,6 @@ where
         use crate::format::Pad::Zero;
         use crate::SecondsFormat::*;
 
-        debug_assert!(secform != __NonExhaustive, "Do not use __NonExhaustive!");
-
         const PREFIX: &[Item<'static>] = &[
             Item::Numeric(Year, Zero),
             Item::Literal("-"),
@@ -721,7 +716,6 @@ where
             Micros => Some(Item::Fixed(Fixed::Nanosecond6)),
             Nanos => Some(Item::Fixed(Fixed::Nanosecond9)),
             AutoSi => Some(Item::Fixed(Fixed::Nanosecond)),
-            __NonExhaustive => unreachable!(),
         };
 
         let tzitem = Item::Fixed(if use_z {
diff --git a/src/datetime/tests.rs b/src/datetime/tests.rs
index 3e8a871f..f81f8744 100644
--- a/src/datetime/tests.rs
+++ b/src/datetime/tests.rs
@@ -693,14 +693,6 @@ fn test_rfc3339_opts() {
     assert_eq!(ut.to_rfc3339_opts(AutoSi, true), "2018-01-11T02:05:13.084660Z");
 }
 
-#[test]
-#[should_panic]
-fn test_rfc3339_opts_nonexhaustive() {
-    use crate::SecondsFormat;
-    let dt = Utc.with_ymd_and_hms(1999, 10, 9, 1, 2, 3).unwrap();
-    dt.to_rfc3339_opts(SecondsFormat::__NonExhaustive, true);
-}
-
 #[test]
 fn test_datetime_from_str() {
     assert_eq!(