13 files changed, 291 insertions, 175 deletions
diff --git a/third_party/rust/serde/.cargo-checksum.json b/third_party/rust/serde/.cargo-checksum.json
index d55068bd63..65bca8af82 100644
--- a/third_party/rust/serde/.cargo-checksum.json
+++ b/third_party/rust/serde/.cargo-checksum.json
@@ -1 +1 @@
-{"files":{"Cargo.toml":"f03b626efae73a6dd42f07d722dad2da3a4add51f4e653e30a6d696853bab209","LICENSE-APACHE":"62c7a1e35f56406896d7aa7ca52d0cc0d272ac022b5d2796e7d6905db8a3636a","LICENSE-MIT":"23f18e03dc49df91622fe2a76176497404e46ced8a715d9d2b67a7446571cca3","README.md":"731c044fc5f98b37a89e9049c9214267db98763309cb63146b45c029640f82a3","build.rs":"f9ba30324b9ce085c903595fb55a5293f8c2348ff36bfe870521b935ae6d105c","crates-io.md":"56e988ac4944c45f5bf5051e3827892ed8fb817853d99d9df1fff6621108e270","src/de/format.rs":"c85071b016df643b161859682d21ce34fa0ebf2a3bdbeeea69859da48f5d934f","src/de/ignored_any.rs":"6480f2b2a83dc4764d01b2eec7309729eef2492eede2e5ee98d23a60b05198eb","src/de/impls.rs":"2857d734176a0b78a41c9358354b0b0b83c6b2d948590be072d98606a8cae9d6","src/de/mod.rs":"fc34da49f692803d2c2f131322d9b48ad8e4f39ed10b2b304d6193ab09d621fb","src/de/seed.rs":"045d890712a04eb33ffc5a021e5d948a63c89402b8ffeea749df2171b7484f8f","src/de/size_hint.rs":"fff83dc39d30e75e8e611991f9c5399188a1aad23a6462dbca2c8b62655cfedb","src/de/value.rs":"0fd511a288c20a1b768718f4baadf9c7d4146d276af6a71ba1d0f7679b28644a","src/integer128.rs":"29ef30b7d94507b34807090e68173767cdc7aff62edccd38affe69e75338dddc","src/lib.rs":"638b231a280519f1861ea5f1bfbe97e2394b2f7662a9701b8e57ed95093dd298","src/macros.rs":"e3486ef4a9a4ed1b27234aa1817ccb25ec0eb026ffc95e2c71c7b917f1f45629","src/private/de.rs":"6557a124fdaf61f9c7cd80163e40f4a453354e45b63a4eb55dafdfe0159f6881","src/private/doc.rs":"9ad740e9ea2eedf861b77116eda9a6fb74bc8553541cd17d1bc5791a3ef3271a","src/private/mod.rs":"b8f0c348621d91dd9da3db83d8877e70bc61ad0a2dc2d6fb57c6fc2c2cbafa26","src/private/ser.rs":"656613691bd8d40cb70a52d4ebe3ee96a993c8a1292d50822d9ca5bdad84426b","src/ser/fmt.rs":"77a5583e5c227ea1982b097ed6378af5c899d43761d71e33440262fd35944695","src/ser/impls.rs":"850619164b399c37cd373d24f5a2c83453f40b34bb978c5722d2c1ae226775b5","src/ser/impossible.rs":"e11b37689ec1395378d546fce74221ca9046d0761744301f12029102fd07e30e","src/ser/mod.rs":"a7fd082203d63cbe4f0fe86d9be16bf4f3b2444653dac6bb61d82e0f4f6b4214","src/std_error.rs":"25a07149e2e468747ffa5a58051c7f93d7b3c0fa0372f012a96c97ec8ab03b97"},"package":"3fb1c873e1b9b056a4dc4c0c198b24c3ffa059243875552b2bd0933b1aee4ce2"}
-\ No newline at end of file
+{"files":{"Cargo.toml":"fcf211f4e710da1375e944a42621a8cd3de8d683db3e464ab570652216015d87","LICENSE-APACHE":"62c7a1e35f56406896d7aa7ca52d0cc0d272ac022b5d2796e7d6905db8a3636a","LICENSE-MIT":"23f18e03dc49df91622fe2a76176497404e46ced8a715d9d2b67a7446571cca3","README.md":"731c044fc5f98b37a89e9049c9214267db98763309cb63146b45c029640f82a3","build.rs":"56b4f43d4061c03fbdd4f6325f30439686b12679bace304223d30c03632a925e","crates-io.md":"56e988ac4944c45f5bf5051e3827892ed8fb817853d99d9df1fff6621108e270","src/de/format.rs":"c85071b016df643b161859682d21ce34fa0ebf2a3bdbeeea69859da48f5d934f","src/de/ignored_any.rs":"6480f2b2a83dc4764d01b2eec7309729eef2492eede2e5ee98d23a60b05198eb","src/de/impls.rs":"cd2781405d8f4568701a701e6b9946e5956eb201571118c8a49038928477779a","src/de/mod.rs":"2be26b699feb8cc0c7f573d58fc11bb92d0b7bd1063bf8fcbd0e71d60f53c99a","src/de/seed.rs":"045d890712a04eb33ffc5a021e5d948a63c89402b8ffeea749df2171b7484f8f","src/de/size_hint.rs":"fff83dc39d30e75e8e611991f9c5399188a1aad23a6462dbca2c8b62655cfedb","src/de/value.rs":"0fd511a288c20a1b768718f4baadf9c7d4146d276af6a71ba1d0f7679b28644a","src/integer128.rs":"29ef30b7d94507b34807090e68173767cdc7aff62edccd38affe69e75338dddc","src/lib.rs":"0e4c06f18a0f2e46d60f54f463e906bf1ba1330ef9820a12173fd28a91b9fcde","src/macros.rs":"e3486ef4a9a4ed1b27234aa1817ccb25ec0eb026ffc95e2c71c7b917f1f45629","src/private/de.rs":"9255ecf2d5c52f0f52b4e0dbf85bdd8c140bc2c1ac96086ee395589e0521aeb4","src/private/doc.rs":"b222decb40321190155209e1b8a5a52e3adfaa470047e379e664b71e0320655a","src/private/mod.rs":"b8f0c348621d91dd9da3db83d8877e70bc61ad0a2dc2d6fb57c6fc2c2cbafa26","src/private/ser.rs":"73577607e779e1b42713c51b9bc7136f99daccf473b4a641c99ceebe46708d47","src/ser/fmt.rs":"d1cfd9623605413e45a23ef778d97f0ac4da4adaed23739f1f9d7414b30e384b","src/ser/impls.rs":"0eebc159f7d3962c46c323e456afb679747ff57563e796c5fd92c64ed074ae70","src/ser/impossible.rs":"5c325da8e0370ab22abe1e15d8af1dc7a1707b127508f61e720cd7f0caa80593","src/ser/mod.rs":"a92d4ce0a6c68eb22a24a61574a5d2e9b0b463b284ff08e62298b8f7ae1a7464","src/std_error.rs":"25a07149e2e468747ffa5a58051c7f93d7b3c0fa0372f012a96c97ec8ab03b97"},"package":"9846a40c979031340571da2545a4e5b7c4163bdae79b301d5f86d03979451fcc"}
+\ No newline at end of file
diff --git a/third_party/rust/serde/Cargo.toml b/third_party/rust/serde/Cargo.toml
index 6ba68688ac..b6f335bafd 100644
--- a/third_party/rust/serde/Cargo.toml
+++ b/third_party/rust/serde/Cargo.toml
@@ -13,7 +13,7 @@
 edition = "2018"
 rust-version = "1.31"
 name = "serde"
-version = "1.0.197"
+version = "1.0.198"
 authors = [
     "Erick Tryzelaar <erick.tryzelaar@gmail.com>",
     "David Tolnay <dtolnay@gmail.com>",
@@ -74,4 +74,4 @@ std = []
 unstable = []
 
 [target."cfg(any())".dependencies.serde_derive]
-version = "=1.0.197"
+version = "=1.0.198"
diff --git a/third_party/rust/serde/build.rs b/third_party/rust/serde/build.rs
index fe5486a7a5..0074df63f4 100644
--- a/third_party/rust/serde/build.rs
+++ b/third_party/rust/serde/build.rs
@@ -64,6 +64,12 @@ fn main() {
     if minor < 64 {
         println!("cargo:rustc-cfg=no_core_cstr");
     }
+
+    // Support for core::num::Saturating and std::num::Saturating stabilized in Rust 1.74
+    // https://blog.rust-lang.org/2023/11/16/Rust-1.74.0.html#stabilized-apis
+    if minor < 74 {
+        println!("cargo:rustc-cfg=no_core_num_saturating");
+    }
 }
 
 fn rustc_minor_version() -> Option<u32> {
diff --git a/third_party/rust/serde/src/de/impls.rs b/third_party/rust/serde/src/de/impls.rs
index 413c997afd..140878aec6 100644
--- a/third_party/rust/serde/src/de/impls.rs
+++ b/third_party/rust/serde/src/de/impls.rs
@@ -104,6 +104,28 @@ macro_rules! impl_deserialize_num {
                 deserializer.$deserialize(NonZeroVisitor)
             }
         }
+
+        #[cfg(not(no_core_num_saturating))]
+        impl<'de> Deserialize<'de> for Saturating<$primitive> {
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+            where
+                D: Deserializer<'de>,
+            {
+                struct SaturatingVisitor;
+
+                impl<'de> Visitor<'de> for SaturatingVisitor {
+                    type Value = Saturating<$primitive>;
+
+                    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                        formatter.write_str("integer with support for saturating semantics")
+                    }
+
+                    $($($method!(saturating $primitive $val : $visit);)*)*
+                }
+
+                deserializer.$deserialize(SaturatingVisitor)
+            }
+        }
     };
 
     ($primitive:ident, $deserialize:ident $($method:ident!($($val:ident : $visit:ident)*);)*) => {
@@ -154,6 +176,15 @@ macro_rules! num_self {
             }
         }
     };
+
+    (saturating $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            Ok(Saturating(v))
+        }
+    };
 }
 
 macro_rules! num_as_self {
@@ -179,6 +210,15 @@ macro_rules! num_as_self {
             }
         }
     };
+
+    (saturating $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            Ok(Saturating(v as $primitive))
+        }
+    };
 }
 
 macro_rules! num_as_copysign_self {
@@ -235,6 +275,21 @@ macro_rules! int_to_int {
             Err(Error::invalid_value(Unexpected::Signed(v as i64), &self))
         }
     };
+
+    (saturating $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if (v as i64) < $primitive::MIN as i64 {
+                Ok(Saturating($primitive::MIN))
+            } else if ($primitive::MAX as i64) < v as i64 {
+                Ok(Saturating($primitive::MAX))
+            } else {
+                Ok(Saturating(v as $primitive))
+            }
+        }
+    };
 }
 
 macro_rules! int_to_uint {
@@ -265,6 +320,21 @@ macro_rules! int_to_uint {
             Err(Error::invalid_value(Unexpected::Signed(v as i64), &self))
         }
     };
+
+    (saturating $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if v < 0 {
+                Ok(Saturating(0))
+            } else if ($primitive::MAX as u64) < v as u64 {
+                Ok(Saturating($primitive::MAX))
+            } else {
+                Ok(Saturating(v as $primitive))
+            }
+        }
+    };
 }
 
 macro_rules! uint_to_self {
@@ -295,6 +365,19 @@ macro_rules! uint_to_self {
             Err(Error::invalid_value(Unexpected::Unsigned(v as u64), &self))
         }
     };
+
+    (saturating $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if v as u64 <= $primitive::MAX as u64 {
+                Ok(Saturating(v as $primitive))
+            } else {
+                Ok(Saturating($primitive::MAX))
+            }
+        }
+    };
 }
 
 impl_deserialize_num! {
@@ -427,6 +510,21 @@ macro_rules! num_128 {
             }
         }
     };
+
+    (saturating $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if (v as i128) < $primitive::MIN as i128 {
+                Ok(Saturating($primitive::MIN))
+            } else if ($primitive::MAX as u128) < v as u128 {
+                Ok(Saturating($primitive::MAX))
+            } else {
+                Ok(Saturating(v as $primitive))
+            }
+        }
+    };
 }
 
 impl_deserialize_num! {
@@ -852,7 +950,10 @@ struct PhantomDataVisitor<T: ?Sized> {
     marker: PhantomData<T>,
 }
 
-impl<'de, T: ?Sized> Visitor<'de> for PhantomDataVisitor<T> {
+impl<'de, T> Visitor<'de> for PhantomDataVisitor<T>
+where
+    T: ?Sized,
+{
     type Value = PhantomData<T>;
 
     fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
@@ -868,7 +969,10 @@ impl<'de, T: ?Sized> Visitor<'de> for PhantomDataVisitor<T> {
     }
 }
 
-impl<'de, T: ?Sized> Deserialize<'de> for PhantomData<T> {
+impl<'de, T> Deserialize<'de> for PhantomData<T>
+where
+    T: ?Sized,
+{
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
         D: Deserializer<'de>,
@@ -1877,9 +1981,9 @@ forwarded_impl! {
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
-impl<'de, 'a, T: ?Sized> Deserialize<'de> for Cow<'a, T>
+impl<'de, 'a, T> Deserialize<'de> for Cow<'a, T>
 where
-    T: ToOwned,
+    T: ?Sized + ToOwned,
     T::Owned: Deserialize<'de>,
 {
     #[inline]
@@ -1902,7 +2006,7 @@ where
     doc_cfg,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
-impl<'de, T: ?Sized> Deserialize<'de> for RcWeak<T>
+impl<'de, T> Deserialize<'de> for RcWeak<T>
 where
     T: Deserialize<'de>,
 {
@@ -1924,7 +2028,7 @@ where
     doc_cfg,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
-impl<'de, T: ?Sized> Deserialize<'de> for ArcWeak<T>
+impl<'de, T> Deserialize<'de> for ArcWeak<T>
 where
     T: Deserialize<'de>,
 {
@@ -1945,8 +2049,9 @@ macro_rules! box_forwarded_impl {
         $t:ident
     ) => {
         $(#[$attr])*
-        impl<'de, T: ?Sized> Deserialize<'de> for $t<T>
+        impl<'de, T> Deserialize<'de> for $t<T>
         where
+            T: ?Sized,
             Box<T>: Deserialize<'de>,
         {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
diff --git a/third_party/rust/serde/src/de/mod.rs b/third_party/rust/serde/src/de/mod.rs
index 1924fe3d88..4c5a5f9b78 100644
--- a/third_party/rust/serde/src/de/mod.rs
+++ b/third_party/rust/serde/src/de/mod.rs
@@ -1735,9 +1735,9 @@ pub trait SeqAccess<'de> {
     }
 }
 
-impl<'de, 'a, A: ?Sized> SeqAccess<'de> for &'a mut A
+impl<'de, 'a, A> SeqAccess<'de> for &'a mut A
 where
-    A: SeqAccess<'de>,
+    A: ?Sized + SeqAccess<'de>,
 {
     type Error = A::Error;
 
@@ -1888,9 +1888,9 @@ pub trait MapAccess<'de> {
     }
 }
 
-impl<'de, 'a, A: ?Sized> MapAccess<'de> for &'a mut A
+impl<'de, 'a, A> MapAccess<'de> for &'a mut A
 where
-    A: MapAccess<'de>,
+    A: ?Sized + MapAccess<'de>,
 {
     type Error = A::Error;
 
diff --git a/third_party/rust/serde/src/lib.rs b/third_party/rust/serde/src/lib.rs
index 5cf44c1c18..fefbf8fda2 100644
--- a/third_party/rust/serde/src/lib.rs
+++ b/third_party/rust/serde/src/lib.rs
@@ -95,7 +95,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.197")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.198")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Show which crate feature enables conditionally compiled APIs in documentation.
@@ -274,6 +274,9 @@ mod lib {
     pub use std::sync::atomic::{AtomicI64, AtomicU64};
     #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "ptr"))]
     pub use std::sync::atomic::{AtomicIsize, AtomicUsize};
+
+    #[cfg(not(no_core_num_saturating))]
+    pub use self::core::num::Saturating;
 }
 
 // None of this crate's error handling needs the `From::from` error conversion
diff --git a/third_party/rust/serde/src/private/de.rs b/third_party/rust/serde/src/private/de.rs
index 883e6909c1..c402d2c66a 100644
--- a/third_party/rust/serde/src/private/de.rs
+++ b/third_party/rust/serde/src/private/de.rs
@@ -313,6 +313,8 @@ mod content {
         }
     }
 
+    /// Used to capture data in [`Content`] from other deserializers.
+    /// Cannot capture externally tagged enums, `i128` and `u128`.
     struct ContentVisitor<'de> {
         value: PhantomData<Content<'de>>,
     }
@@ -528,6 +530,8 @@ mod content {
         Content(Content<'de>),
     }
 
+    /// Serves as a seed for deserializing a key of internally tagged enum.
+    /// Cannot capture externally tagged enums, `i128` and `u128`.
     struct TagOrContentVisitor<'de> {
         name: &'static str,
         value: PhantomData<TagOrContent<'de>>,
@@ -814,6 +818,9 @@ mod content {
 
     /// Used by generated code to deserialize an internally tagged enum.
     ///
+    /// Captures map or sequence from the original deserializer and searches
+    /// a tag in it (in case of sequence, tag is the first element of sequence).
+    ///
     /// Not public API.
     pub struct TaggedContentVisitor<T> {
         tag_name: &'static str,
diff --git a/third_party/rust/serde/src/private/doc.rs b/third_party/rust/serde/src/private/doc.rs
index 1b18fe6b41..1f17c8db53 100644
--- a/third_party/rust/serde/src/private/doc.rs
+++ b/third_party/rust/serde/src/private/doc.rs
@@ -56,7 +56,10 @@ macro_rules! __serialize_unimplemented {
 #[macro_export]
 macro_rules! __serialize_unimplemented_method {
     ($func:ident $(<$t:ident>)* ($($arg:ty),*) -> $ret:ident) => {
-        fn $func $(<$t: ?Sized + $crate::Serialize>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error> {
+        fn $func $(<$t>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error>
+        where
+            $($t: ?Sized + $crate::Serialize,)*
+        {
             unimplemented!()
         }
     };
diff --git a/third_party/rust/serde/src/private/ser.rs b/third_party/rust/serde/src/private/ser.rs
index 50bcb251e3..40cc6cbdb7 100644
--- a/third_party/rust/serde/src/private/ser.rs
+++ b/third_party/rust/serde/src/private/ser.rs
@@ -174,9 +174,9 @@ where
         Err(self.bad_type(Unsupported::Optional))
     }
 
-    fn serialize_some<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, _: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Err(self.bad_type(Unsupported::Optional))
     }
@@ -205,18 +205,18 @@ where
         map.end()
     }
 
-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
         self,
         _: &'static str,
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         value.serialize(self)
     }
 
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         _: &'static str,
         _: u32,
@@ -224,7 +224,7 @@ where
         inner_value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let mut map = tri!(self.delegate.serialize_map(Some(2)));
         tri!(map.serialize_entry(self.tag, self.variant_name));
@@ -327,9 +327,9 @@ where
     }
 
     #[cfg(not(any(feature = "std", feature = "alloc")))]
-    fn collect_str<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, _: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Display,
+        T: ?Sized + Display,
     {
         Err(self.bad_type(Unsupported::String))
     }
@@ -364,9 +364,9 @@ mod content {
         type Ok = M::Ok;
         type Error = M::Error;
 
-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), M::Error>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), M::Error>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
             self.fields.push(value);
@@ -404,13 +404,9 @@ mod content {
         type Ok = M::Ok;
         type Error = M::Error;
 
-        fn serialize_field<T: ?Sized>(
-            &mut self,
-            key: &'static str,
-            value: &T,
-        ) -> Result<(), M::Error>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), M::Error>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
             self.fields.push((key, value));
@@ -635,9 +631,9 @@ mod content {
             Ok(Content::None)
         }
 
-        fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Content, E>
+        fn serialize_some<T>(self, value: &T) -> Result<Content, E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             Ok(Content::Some(Box::new(tri!(value.serialize(self)))))
         }
@@ -659,13 +655,9 @@ mod content {
             Ok(Content::UnitVariant(name, variant_index, variant))
         }
 
-        fn serialize_newtype_struct<T: ?Sized>(
-            self,
-            name: &'static str,
-            value: &T,
-        ) -> Result<Content, E>
+        fn serialize_newtype_struct<T>(self, name: &'static str, value: &T) -> Result<Content, E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             Ok(Content::NewtypeStruct(
                 name,
@@ -673,7 +665,7 @@ mod content {
             ))
         }
 
-        fn serialize_newtype_variant<T: ?Sized>(
+        fn serialize_newtype_variant<T>(
             self,
             name: &'static str,
             variant_index: u32,
@@ -681,7 +673,7 @@ mod content {
             value: &T,
         ) -> Result<Content, E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             Ok(Content::NewtypeVariant(
                 name,
@@ -782,9 +774,9 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_element<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.elements.push(value);
@@ -808,9 +800,9 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_element<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.elements.push(value);
@@ -835,9 +827,9 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push(value);
@@ -864,9 +856,9 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push(value);
@@ -896,18 +888,18 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), E>
+        fn serialize_key<T>(&mut self, key: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let key = tri!(key.serialize(ContentSerializer::<E>::new()));
             self.key = Some(key);
             Ok(())
         }
 
-        fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        fn serialize_value<T>(&mut self, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let key = self
                 .key
@@ -922,10 +914,10 @@ mod content {
             Ok(Content::Map(self.entries))
         }
 
-        fn serialize_entry<K: ?Sized, V: ?Sized>(&mut self, key: &K, value: &V) -> Result<(), E>
+        fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), E>
         where
-            K: Serialize,
-            V: Serialize,
+            K: ?Sized + Serialize,
+            V: ?Sized + Serialize,
         {
             let key = tri!(key.serialize(ContentSerializer::<E>::new()));
             let value = tri!(value.serialize(ContentSerializer::<E>::new()));
@@ -947,9 +939,9 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push((key, value));
@@ -976,9 +968,9 @@ mod content {
         type Ok = Content;
         type Error = E;
 
-        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), E>
         where
-            T: Serialize,
+            T: ?Sized + Serialize,
         {
             let value = tri!(value.serialize(ContentSerializer::<E>::new()));
             self.fields.push((key, value));
@@ -1088,9 +1080,9 @@ where
         Ok(())
     }
 
-    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         value.serialize(self)
     }
@@ -1112,18 +1104,18 @@ where
         Err(Self::bad_type(Unsupported::Enum))
     }
 
-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
         self,
         _: &'static str,
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         value.serialize(self)
     }
 
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         _: &'static str,
         _: u32,
@@ -1131,7 +1123,7 @@ where
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         tri!(self.0.serialize_key(variant));
         self.0.serialize_value(value)
@@ -1202,28 +1194,24 @@ where
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         self.0.serialize_key(key)
     }
 
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         self.0.serialize_value(value)
     }
 
-    fn serialize_entry<K: ?Sized, V: ?Sized>(
-        &mut self,
-        key: &K,
-        value: &V,
-    ) -> Result<(), Self::Error>
+    fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), Self::Error>
     where
-        K: Serialize,
-        V: Serialize,
+        K: ?Sized + Serialize,
+        V: ?Sized + Serialize,
     {
         self.0.serialize_entry(key, value)
     }
@@ -1244,13 +1232,9 @@ where
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         self.0.serialize_entry(key, value)
     }
@@ -1289,9 +1273,9 @@ where
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
         self.fields.push(value);
@@ -1335,13 +1319,9 @@ where
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
         self.fields.push((key, value));
diff --git a/third_party/rust/serde/src/ser/fmt.rs b/third_party/rust/serde/src/ser/fmt.rs
index 0650ab6f12..04684aded0 100644
--- a/third_party/rust/serde/src/ser/fmt.rs
+++ b/third_party/rust/serde/src/ser/fmt.rs
@@ -74,9 +74,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Display::fmt(variant, self)
     }
 
-    fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> fmt::Result
+    fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> fmt::Result
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Serialize::serialize(value, self)
     }
@@ -89,9 +89,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Err(fmt::Error)
     }
 
-    fn serialize_some<T: ?Sized>(self, _value: &T) -> fmt::Result
+    fn serialize_some<T>(self, _value: &T) -> fmt::Result
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Err(fmt::Error)
     }
@@ -100,7 +100,7 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Err(fmt::Error)
     }
 
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         _name: &'static str,
         _variant_index: u32,
@@ -108,7 +108,7 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         _value: &T,
     ) -> fmt::Result
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         Err(fmt::Error)
     }
@@ -161,9 +161,9 @@ impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
         Err(fmt::Error)
     }
 
-    fn collect_str<T: ?Sized>(self, value: &T) -> fmt::Result
+    fn collect_str<T>(self, value: &T) -> fmt::Result
     where
-        T: Display,
+        T: ?Sized + Display,
     {
         Display::fmt(value, self)
     }
diff --git a/third_party/rust/serde/src/ser/impls.rs b/third_party/rust/serde/src/ser/impls.rs
index 8c70634af0..ffc4c70f90 100644
--- a/third_party/rust/serde/src/ser/impls.rs
+++ b/third_party/rust/serde/src/ser/impls.rs
@@ -114,7 +114,10 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-impl<T: ?Sized> Serialize for PhantomData<T> {
+impl<T> Serialize for PhantomData<T>
+where
+    T: ?Sized,
+{
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -504,17 +507,17 @@ macro_rules! deref_impl {
 }
 
 deref_impl! {
-    <'a, T: ?Sized> Serialize for &'a T where T: Serialize
+    <'a, T> Serialize for &'a T where T: ?Sized + Serialize
 }
 
 deref_impl! {
-    <'a, T: ?Sized> Serialize for &'a mut T where T: Serialize
+    <'a, T> Serialize for &'a mut T where T: ?Sized + Serialize
 }
 
 deref_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
     #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
-    <T: ?Sized> Serialize for Box<T> where T: Serialize
+    <T> Serialize for Box<T> where T: ?Sized + Serialize
 }
 
 deref_impl! {
@@ -528,7 +531,7 @@ deref_impl! {
     /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
     #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
     #[cfg_attr(doc_cfg, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
-    <T: ?Sized> Serialize for Rc<T> where T: Serialize
+    <T> Serialize for Rc<T> where T: ?Sized + Serialize
 }
 
 deref_impl! {
@@ -542,13 +545,13 @@ deref_impl! {
     /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
     #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
     #[cfg_attr(doc_cfg, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
-    <T: ?Sized> Serialize for Arc<T> where T: Serialize
+    <T> Serialize for Arc<T> where T: ?Sized + Serialize
 }
 
 deref_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
     #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
-    <'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwned
+    <'a, T> Serialize for Cow<'a, T> where T: ?Sized + Serialize + ToOwned
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -561,9 +564,9 @@ deref_impl! {
     doc_cfg,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
-impl<T: ?Sized> Serialize for RcWeak<T>
+impl<T> Serialize for RcWeak<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -581,9 +584,9 @@ where
     doc_cfg,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
-impl<T: ?Sized> Serialize for ArcWeak<T>
+impl<T> Serialize for ArcWeak<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -641,9 +644,9 @@ where
     }
 }
 
-impl<T: ?Sized> Serialize for RefCell<T>
+impl<T> Serialize for RefCell<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -658,9 +661,9 @@ where
 
 #[cfg(feature = "std")]
 #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
-impl<T: ?Sized> Serialize for Mutex<T>
+impl<T> Serialize for Mutex<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -675,9 +678,9 @@ where
 
 #[cfg(feature = "std")]
 #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
-impl<T: ?Sized> Serialize for RwLock<T>
+impl<T> Serialize for RwLock<T>
 where
-    T: Serialize,
+    T: ?Sized + Serialize,
 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -1023,6 +1026,20 @@ where
     }
 }
 
+#[cfg(not(no_core_num_saturating))]
+impl<T> Serialize for Saturating<T>
+where
+    T: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.0.serialize(serializer)
+    }
+}
+
 impl<T> Serialize for Reverse<T>
 where
     T: Serialize,
diff --git a/third_party/rust/serde/src/ser/impossible.rs b/third_party/rust/serde/src/ser/impossible.rs
index 479be94071..6432d5775a 100644
--- a/third_party/rust/serde/src/ser/impossible.rs
+++ b/third_party/rust/serde/src/ser/impossible.rs
@@ -72,9 +72,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -92,9 +92,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -112,9 +112,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -132,9 +132,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -152,17 +152,17 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = key;
         match self.void {}
     }
 
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = value;
         match self.void {}
@@ -180,9 +180,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = key;
         let _ = value;
@@ -201,9 +201,9 @@ where
     type Ok = Ok;
     type Error = Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
     where
-        T: Serialize,
+        T: ?Sized + Serialize,
     {
         let _ = key;
         let _ = value;
diff --git a/third_party/rust/serde/src/ser/mod.rs b/third_party/rust/serde/src/ser/mod.rs
index 75c45140e2..74b5e07691 100644
--- a/third_party/rust/serde/src/ser/mod.rs
+++ b/third_party/rust/serde/src/ser/mod.rs
@@ -796,9 +796,9 @@ pub trait Serializer: Sized {
     /// ```
     ///
     /// [`Some(T)`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some
-    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn serialize_some<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a `()` value.
     ///
@@ -891,13 +891,13 @@ pub trait Serializer: Sized {
     ///     }
     /// }
     /// ```
-    fn serialize_newtype_struct<T: ?Sized>(
+    fn serialize_newtype_struct<T>(
         self,
         name: &'static str,
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a newtype variant like `E::N` in `enum E { N(u8) }`.
     ///
@@ -925,7 +925,7 @@ pub trait Serializer: Sized {
     ///     }
     /// }
     /// ```
-    fn serialize_newtype_variant<T: ?Sized>(
+    fn serialize_newtype_variant<T>(
         self,
         name: &'static str,
         variant_index: u32,
@@ -933,7 +933,7 @@ pub trait Serializer: Sized {
         value: &T,
     ) -> Result<Self::Ok, Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Begin to serialize a variably sized sequence. This call must be
     /// followed by zero or more calls to `serialize_element`, then a call to
@@ -1170,7 +1170,8 @@ pub trait Serializer: Sized {
     /// then a call to `end`.
     ///
     /// The `name` is the name of the struct and the `len` is the number of
-    /// data fields that will be serialized.
+    /// data fields that will be serialized. `len` does not include fields
+    /// which are skipped with [`SerializeStruct::skip_field`].
     ///
     /// ```edition2021
     /// use serde::ser::{Serialize, SerializeStruct, Serializer};
@@ -1207,6 +1208,8 @@ pub trait Serializer: Sized {
     /// The `name` is the name of the enum, the `variant_index` is the index of
     /// this variant within the enum, the `variant` is the name of the variant,
     /// and the `len` is the number of data fields that will be serialized.
+    /// `len` does not include fields which are skipped with
+    /// [`SerializeStructVariant::skip_field`].
     ///
     /// ```edition2021
     /// use serde::ser::{Serialize, SerializeStructVariant, Serializer};
@@ -1346,9 +1349,9 @@ pub trait Serializer: Sized {
     /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
     /// [`serialize_str`]: #tymethod.serialize_str
     #[cfg(any(feature = "std", feature = "alloc"))]
-    fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Display,
+        T: ?Sized + Display,
     {
         self.serialize_str(&value.to_string())
     }
@@ -1379,9 +1382,9 @@ pub trait Serializer: Sized {
     /// }
     /// ```
     #[cfg(not(any(feature = "std", feature = "alloc")))]
-    fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    fn collect_str<T>(self, value: &T) -> Result<Self::Ok, Self::Error>
     where
-        T: Display;
+        T: ?Sized + Display;
 
     /// Determine whether `Serialize` implementations should serialize in
     /// human-readable form.
@@ -1493,9 +1496,9 @@ pub trait SerializeSeq {
     type Error: Error;
 
     /// Serialize a sequence element.
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a sequence.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1593,9 +1596,9 @@ pub trait SerializeTuple {
     type Error: Error;
 
     /// Serialize a tuple element.
-    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_element<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a tuple.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1638,9 +1641,9 @@ pub trait SerializeTupleStruct {
     type Error: Error;
 
     /// Serialize a tuple struct field.
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a tuple struct.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1696,9 +1699,9 @@ pub trait SerializeTupleVariant {
     type Error: Error;
 
     /// Serialize a tuple variant field.
-    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Finish serializing a tuple variant.
     fn end(self) -> Result<Self::Ok, Self::Error>;
@@ -1767,9 +1770,9 @@ pub trait SerializeMap {
     /// `serialize_entry` instead as it may be implemented more efficiently in
     /// some formats compared to a pair of calls to `serialize_key` and
     /// `serialize_value`.
-    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    fn serialize_key<T>(&mut self, key: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a map value.
     ///
@@ -1777,9 +1780,9 @@ pub trait SerializeMap {
     ///
     /// Calling `serialize_value` before `serialize_key` is incorrect and is
     /// allowed to panic or produce bogus results.
-    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    fn serialize_value<T>(&mut self, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Serialize a map entry consisting of a key and a value.
     ///
@@ -1798,14 +1801,10 @@ pub trait SerializeMap {
     /// [`Serialize`]: ../trait.Serialize.html
     /// [`serialize_key`]: #tymethod.serialize_key
     /// [`serialize_value`]: #tymethod.serialize_value
-    fn serialize_entry<K: ?Sized, V: ?Sized>(
-        &mut self,
-        key: &K,
-        value: &V,
-    ) -> Result<(), Self::Error>
+    fn serialize_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), Self::Error>
     where
-        K: Serialize,
-        V: Serialize,
+        K: ?Sized + Serialize,
+        V: ?Sized + Serialize,
     {
         tri!(self.serialize_key(key));
         self.serialize_value(value)
@@ -1856,15 +1855,13 @@ pub trait SerializeStruct {
     type Error: Error;
 
     /// Serialize a struct field.
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Indicate that a struct field has been skipped.
+    ///
+    /// The default implementation does nothing.
     #[inline]
     fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> {
         let _ = key;
@@ -1922,15 +1919,13 @@ pub trait SerializeStructVariant {
     type Error: Error;
 
     /// Serialize a struct variant field.
-    fn serialize_field<T: ?Sized>(
-        &mut self,
-        key: &'static str,
-        value: &T,
-    ) -> Result<(), Self::Error>
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
     where
-        T: Serialize;
+        T: ?Sized + Serialize;
 
     /// Indicate that a struct variant field has been skipped.
+    ///
+    /// The default implementation does nothing.
     #[inline]
     fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> {
         let _ = key;