span: remove the PartialEq and Eq trait implementations

Fixes #32

CHANGELOG.md

@@ -9,6 +9,12 @@
 The deprecated `intz` routines on `Zoned`, `Timestamp`, `civil::DateTime` and
 `civil::Date` have been removed. You can use `in_tz` instead. This change was
 made because many found the name `intz` to be unclear.
+* [#32](https://github.com/BurntSushi/jiff/issues/32):
+The `PartialEq` and `Eq` trait implementations on `Span` have been removed.
+Ideally these shouldn't have been used, but if you do need them, please use
+`Span::fieldwise` to create a `SpanFieldwise`, which does have the `PartialEq`
+and `Eq` traits implemented. These were removed on `Span` itself because they
+made it very easy to commit subtle bugs.
 * [#36](https://github.com/BurntSushi/jiff/issues/36):
 Turn panics during `Timestamp::saturing_add` into errors. Callers adding
 spans that are known to contain units of hours or smaller are guaranteed that

bench/src/bench.rs

@@ -673,7 +673,7 @@ fn parse_friendly(c: &mut Criterion) {
         c.bench_function(&format!("jiff-span/{NAME}/{kind}"), |b| {
             b.iter(|| {
                 let got: jiff::Span = input.parse().unwrap();
-                assert_eq!(got, expected);
+                assert_eq!(got.fieldwise(), expected.fieldwise());
             })
         });
     }

src/span.rs

@@ -294,24 +294,22 @@ pub(crate) use span_eq;
 ///
 /// # Comparisons
 ///
-/// While a `Span` currently implements the `PartialEq` and `Eq` traits, these
-/// implementations are deprecated and will be removed in `jiff 0.2`. The trait
-/// implementations only do comparisons based on the fields in the `Span` and
-/// do not take total duration into account. These were deprecated because
-/// it made it too easy to introduce bugs. For example, `120.minutes()` and
-/// `2.hours()` always correspond to the same total duration, but they have
-/// different representations in memory.
+/// A `Span` does not implement the `PartialEq` or `Eq` traits. These traits
+/// were implemented in an earlier version of Jiff, but they made it too
+/// easy to introduce bugs. For example, `120.minutes()` and `2.hours()`
+/// always correspond to the same total duration, but they have different
+/// representations in memory and so didn't compare equivalent.
 ///
 /// The reason why the `PartialEq` and `Eq` trait implementations do not do
 /// comparisons with total duration is because it is fundamentally impossible
 /// to do such comparisons without a reference date in all cases.
 ///
-/// However, it is undeniably occasionally useful to do comparisons based on
-/// the component fields, so long as such use cases can tolerate two different
-/// spans comparing unequal even when their total durations are equivalent. For
-/// example, many of the tests in Jiff (including the tests in the documentation)
-/// work by comparing a `Span` to an expected result. This is a good demonstration
-/// of when fieldwise comparisons are appropriate.
+/// However, it is undeniably occasionally useful to do comparisons based
+/// on the component fields, so long as such use cases can tolerate two
+/// different spans comparing unequal even when their total durations are
+/// equivalent. For example, many of the tests in Jiff (including the tests in
+/// the documentation) work by comparing a `Span` to an expected result. This
+/// is a good demonstration of when fieldwise comparisons are appropriate.
 ///
 /// To do fieldwise comparisons with a span, use the [`Span::fieldwise`]
 /// method. This method creates a [`SpanFieldwise`], which is just a `Span`
@@ -1407,11 +1405,6 @@ impl Span {
     /// field values. For example, Jiff itself makes heavy use of fieldwise
     /// comparisons for tests.
     ///
-    /// **NOTE:** In `jiff 0.1`, the `Span` type itself also implements the
-    /// `Eq` and `PartialEq` traits. This was considered a bug in the API and
-    /// these trait implementations have been deprecated and will be removed
-    /// in `jiff 0.2`.
-    ///
     /// # Example: the difference between `SpanFieldwise` and `Span::compare`
     ///
     /// In short, `SpanFieldwise` considers `2 hours` and `120 minutes` to be
@@ -3330,26 +3323,6 @@ impl Default for Span {
     }
 }
 
-/// DEPRECATED since `jiff 0.1.25`.
-///
-/// Please use [`Span::fieldwise`] to create a span that can be compared by its
-/// fields.
-///
-/// This trait implementation will be removed in `jiff 0.2`.
-impl Eq for Span {}
-
-/// DEPRECATED since `jiff 0.1.25`.
-///
-/// Please use [`Span::fieldwise`] to create a span that can be compared by its
-/// fields.
-///
-/// This trait implementation will be removed in `jiff 0.2`.
-impl PartialEq for Span {
-    fn eq(&self, rhs: &Span) -> bool {
-        self.fieldwise() == rhs.fieldwise()
-    }
-}
-
 impl core::fmt::Debug for Span {
     #[inline]
     fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
@@ -3857,11 +3830,6 @@ impl quickcheck::Arbitrary for Span {
 /// values. For example, Jiff itself makes heavy use of fieldwise comparisons
 /// for tests.
 ///
-/// **NOTE:** In `jiff 0.1`, the `Span` type itself also implements the
-/// `Eq` and `PartialEq` traits. This was considered a bug in the API and
-/// these trait implementations have been deprecated and will be removed
-/// in `jiff 0.2`.
-///
 /// # Construction
 ///
 /// While callers may use `SpanFieldwise(span)` (where `span` has type [`Span`])