From a8f14840ab3ff58f533cd27d0f91955d57f12a65 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sat, 18 May 2024 21:16:37 -0700
Subject: [PATCH] Rely on docs.rs to define --cfg=docsrs by default

---
 serde/Cargo.toml       |  2 +-
 serde/build.rs         |  1 -
 serde/src/de/impls.rs  | 70 +++++++++++++++++++++---------------------
 serde/src/de/mod.rs    |  4 +--
 serde/src/de/value.rs  | 24 +++++++--------
 serde/src/lib.rs       |  4 +--
 serde/src/ser/impls.rs | 64 +++++++++++++++++++-------------------
 7 files changed, 84 insertions(+), 85 deletions(-)

diff --git a/serde/Cargo.toml b/serde/Cargo.toml
index 1dea49bc4..3a7ce5e79 100644
--- a/serde/Cargo.toml
+++ b/serde/Cargo.toml
@@ -29,7 +29,7 @@ features = ["derive", "rc"]
 [package.metadata.docs.rs]
 features = ["derive", "rc", "unstable"]
 targets = ["x86_64-unknown-linux-gnu"]
-rustdoc-args = ["--cfg", "doc_cfg", "--generate-link-to-definition"]
+rustdoc-args = ["--generate-link-to-definition"]
 
 # This cfg cannot be enabled, but it still forces Cargo to keep serde_derive's
 # version in lockstep with serde's, even if someone depends on the two crates
diff --git a/serde/build.rs b/serde/build.rs
index 097e5f98f..46ca435d5 100644
--- a/serde/build.rs
+++ b/serde/build.rs
@@ -14,7 +14,6 @@ fn main() {
     };
 
     if minor >= 77 {
-        println!("cargo:rustc-check-cfg=cfg(doc_cfg)");
         println!("cargo:rustc-check-cfg=cfg(no_core_cstr)");
         println!("cargo:rustc-check-cfg=cfg(no_core_num_saturating)");
         println!("cargo:rustc-check-cfg=cfg(no_core_try_from)");
diff --git a/serde/src/de/impls.rs b/serde/src/de/impls.rs
index 140878aec..f26b20d46 100644
--- a/serde/src/de/impls.rs
+++ b/serde/src/de/impls.rs
@@ -39,7 +39,7 @@ impl<'de> Deserialize<'de> for () {
 }
 
 #[cfg(feature = "unstable")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "unstable")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 impl<'de> Deserialize<'de> for ! {
     fn deserialize<D>(_deserializer: D) -> Result<Self, D::Error>
     where
@@ -695,7 +695,7 @@ impl<'a, 'de> Visitor<'de> for StringInPlaceVisitor<'a> {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de> Deserialize<'de> for String {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -839,7 +839,7 @@ impl<'de> Visitor<'de> for CStringVisitor {
 }
 
 #[cfg(any(feature = "std", all(not(no_core_cstr), feature = "alloc")))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de> Deserialize<'de> for CString {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -868,7 +868,7 @@ macro_rules! forwarded_impl {
 
 forwarded_impl! {
     #[cfg(any(feature = "std", all(not(no_core_cstr), feature = "alloc")))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     (), Box<CStr>, CString::into_boxed_c_str
 }
 
@@ -1086,7 +1086,7 @@ fn nop_reserve<T>(_seq: T, _n: usize) {}
 
 seq_impl!(
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     BinaryHeap<T: Ord>,
     seq,
     BinaryHeap::clear,
@@ -1097,7 +1097,7 @@ seq_impl!(
 
 seq_impl!(
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     BTreeSet<T: Eq + Ord>,
     seq,
     BTreeSet::clear,
@@ -1108,7 +1108,7 @@ seq_impl!(
 
 seq_impl!(
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     LinkedList<T>,
     seq,
     LinkedList::clear,
@@ -1119,7 +1119,7 @@ seq_impl!(
 
 seq_impl!(
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     HashSet<T: Eq + Hash, S: BuildHasher + Default>,
     seq,
     HashSet::clear,
@@ -1130,7 +1130,7 @@ seq_impl!(
 
 seq_impl!(
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     VecDeque<T>,
     seq,
     VecDeque::clear,
@@ -1142,7 +1142,7 @@ seq_impl!(
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, T> Deserialize<'de> for Vec<T>
 where
     T: Deserialize<'de>,
@@ -1546,7 +1546,7 @@ macro_rules! map_impl {
 
 map_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     BTreeMap<K: Ord, V>,
     map,
     BTreeMap::new(),
@@ -1554,7 +1554,7 @@ map_impl! {
 
 map_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     HashMap<K: Eq + Hash, V, S: BuildHasher + Default>,
     map,
     HashMap::with_capacity_and_hasher(size_hint::cautious::<(K, V)>(map.size_hint()), S::default()),
@@ -1696,7 +1696,7 @@ macro_rules! deserialize_enum {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de> Deserialize<'de> for net::IpAddr {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -1717,13 +1717,13 @@ impl<'de> Deserialize<'de> for net::IpAddr {
 
 parse_ip_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     net::Ipv4Addr, "IPv4 address", 4
 }
 
 parse_ip_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     net::Ipv6Addr, "IPv6 address", 16
 }
 
@@ -1750,7 +1750,7 @@ macro_rules! parse_socket_impl {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de> Deserialize<'de> for net::SocketAddr {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -1771,14 +1771,14 @@ impl<'de> Deserialize<'de> for net::SocketAddr {
 
 parse_socket_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     net::SocketAddrV4, "IPv4 socket address",
     |(ip, port)| net::SocketAddrV4::new(ip, port),
 }
 
 parse_socket_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     net::SocketAddrV6, "IPv6 socket address",
     |(ip, port)| net::SocketAddrV6::new(ip, port, 0, 0),
 }
@@ -1814,7 +1814,7 @@ impl<'a> Visitor<'a> for PathVisitor {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de: 'a, 'a> Deserialize<'de> for &'a Path {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -1869,7 +1869,7 @@ impl<'de> Visitor<'de> for PathBufVisitor {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de> Deserialize<'de> for PathBuf {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -1881,7 +1881,7 @@ impl<'de> Deserialize<'de> for PathBuf {
 
 forwarded_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     (), Box<Path>, PathBuf::into_boxed_path
 }
 
@@ -1943,7 +1943,7 @@ impl<'de> Visitor<'de> for OsStringVisitor {
 }
 
 #[cfg(all(feature = "std", any(unix, windows)))]
-#[cfg_attr(doc_cfg, doc(cfg(all(feature = "std", any(unix, windows)))))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
 impl<'de> Deserialize<'de> for OsString {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -1957,30 +1957,30 @@ impl<'de> Deserialize<'de> for OsString {
 
 forwarded_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     (T), Box<T>, Box::new
 }
 
 forwarded_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     (T), Box<[T]>, Vec::into_boxed_slice
 }
 
 forwarded_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     (), Box<str>, String::into_boxed_str
 }
 
 forwarded_impl! {
     #[cfg(all(feature = "std", any(unix, windows)))]
-    #[cfg_attr(doc_cfg, doc(cfg(all(feature = "std", any(unix, windows)))))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
     (), Box<OsStr>, OsString::into_boxed_os_str
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, 'a, T> Deserialize<'de> for Cow<'a, T>
 where
     T: ?Sized + ToOwned,
@@ -2003,7 +2003,7 @@ where
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 #[cfg_attr(
-    doc_cfg,
+    docsrs,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
 impl<'de, T> Deserialize<'de> for RcWeak<T>
@@ -2025,7 +2025,7 @@ where
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 #[cfg_attr(
-    doc_cfg,
+    docsrs,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
 impl<'de, T> Deserialize<'de> for ArcWeak<T>
@@ -2073,7 +2073,7 @@ box_forwarded_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")))))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
     Rc
 }
 
@@ -2086,7 +2086,7 @@ box_forwarded_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")))))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
     Arc
 }
 
@@ -2110,13 +2110,13 @@ forwarded_impl! {
 
 forwarded_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     (T), Mutex<T>, Mutex::new
 }
 
 forwarded_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     (T), RwLock<T>, RwLock::new
 }
 
@@ -2271,7 +2271,7 @@ impl<'de> Deserialize<'de> for Duration {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de> Deserialize<'de> for SystemTime {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -3107,7 +3107,7 @@ macro_rules! atomic_impl {
     ($($ty:ident $size:expr)*) => {
         $(
             #[cfg(any(no_target_has_atomic, target_has_atomic = $size))]
-            #[cfg_attr(doc_cfg, doc(cfg(all(feature = "std", target_has_atomic = $size))))]
+            #[cfg_attr(docsrs, doc(cfg(all(feature = "std", target_has_atomic = $size))))]
             impl<'de> Deserialize<'de> for $ty {
                 fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
                 where
diff --git a/serde/src/de/mod.rs b/serde/src/de/mod.rs
index 47d5ab8b0..602054a18 100644
--- a/serde/src/de/mod.rs
+++ b/serde/src/de/mod.rs
@@ -1525,7 +1525,7 @@ pub trait Visitor<'de>: Sized {
     /// `String`.
     #[inline]
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
     where
         E: Error,
@@ -1584,7 +1584,7 @@ pub trait Visitor<'de>: Sized {
     /// The default implementation forwards to `visit_bytes` and then drops the
     /// `Vec<u8>`.
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
     where
         E: Error,
diff --git a/serde/src/de/value.rs b/serde/src/de/value.rs
index 3bc0c71c5..1ec947786 100644
--- a/serde/src/de/value.rs
+++ b/serde/src/de/value.rs
@@ -112,7 +112,7 @@ impl Debug for Error {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl error::Error for Error {
     fn description(&self) -> &str {
         &self.err
@@ -185,14 +185,14 @@ impl<E> Debug for UnitDeserializer<E> {
 
 /// A deserializer that cannot be instantiated.
 #[cfg(feature = "unstable")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "unstable")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 pub struct NeverDeserializer<E> {
     never: !,
     marker: PhantomData<E>,
 }
 
 #[cfg(feature = "unstable")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "unstable")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 impl<'de, E> IntoDeserializer<'de, E> for !
 where
     E: de::Error,
@@ -565,7 +565,7 @@ impl<'de, E> Debug for BorrowedStrDeserializer<'de, E> {
 
 /// A deserializer holding a `String`.
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 pub struct StringDeserializer<E> {
     value: String,
     marker: PhantomData<E>,
@@ -582,7 +582,7 @@ impl<E> Clone for StringDeserializer<E> {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, E> IntoDeserializer<'de, E> for String
 where
     E: de::Error,
@@ -670,7 +670,7 @@ impl<E> Debug for StringDeserializer<E> {
 
 /// A deserializer holding a `Cow<str>`.
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 pub struct CowStrDeserializer<'a, E> {
     value: Cow<'a, str>,
     marker: PhantomData<E>,
@@ -687,7 +687,7 @@ impl<'a, E> Clone for CowStrDeserializer<'a, E> {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, 'a, E> IntoDeserializer<'de, E> for Cow<'a, str>
 where
     E: de::Error,
@@ -1006,7 +1006,7 @@ where
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, T, E> IntoDeserializer<'de, E> for Vec<T>
 where
     T: IntoDeserializer<'de, E>,
@@ -1020,7 +1020,7 @@ where
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, T, E> IntoDeserializer<'de, E> for BTreeSet<T>
 where
     T: IntoDeserializer<'de, E> + Eq + Ord,
@@ -1034,7 +1034,7 @@ where
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de, T, S, E> IntoDeserializer<'de, E> for HashSet<T, S>
 where
     T: IntoDeserializer<'de, E> + Eq + Hash,
@@ -1421,7 +1421,7 @@ impl Expected for ExpectedInMap {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl<'de, K, V, E> IntoDeserializer<'de, E> for BTreeMap<K, V>
 where
     K: IntoDeserializer<'de, E> + Eq + Ord,
@@ -1436,7 +1436,7 @@ where
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<'de, K, V, S, E> IntoDeserializer<'de, E> for HashMap<K, V, S>
 where
     K: IntoDeserializer<'de, E> + Eq + Hash,
diff --git a/serde/src/lib.rs b/serde/src/lib.rs
index 308895da1..3185d340e 100644
--- a/serde/src/lib.rs
+++ b/serde/src/lib.rs
@@ -99,7 +99,7 @@
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Show which crate feature enables conditionally compiled APIs in documentation.
-#![cfg_attr(doc_cfg, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 // Unstable functionality only if the user asks for it. For tracking and
 // discussion of these features please refer to this issue:
 //
@@ -330,7 +330,7 @@ extern crate serde_derive;
 
 /// Derive macro available if serde is built with `features = ["derive"]`.
 #[cfg(feature = "serde_derive")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "derive")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "derive")))]
 pub use serde_derive::{Deserialize, Serialize};
 
 #[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
diff --git a/serde/src/ser/impls.rs b/serde/src/ser/impls.rs
index ffc4c70f9..70711afd4 100644
--- a/serde/src/ser/impls.rs
+++ b/serde/src/ser/impls.rs
@@ -48,7 +48,7 @@ impl Serialize for str {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl Serialize for String {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -71,7 +71,7 @@ impl<'a> Serialize for fmt::Arguments<'a> {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", not(no_core_cstr)))]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for CStr {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -83,7 +83,7 @@ impl Serialize for CStr {
 }
 
 #[cfg(any(feature = "std", all(not(no_core_cstr), feature = "alloc")))]
-#[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
 impl Serialize for CString {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -232,37 +232,37 @@ macro_rules! seq_impl {
 
 seq_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     BinaryHeap<T: Ord>
 }
 
 seq_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     BTreeSet<T: Ord>
 }
 
 seq_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     HashSet<T: Eq + Hash, H: BuildHasher>
 }
 
 seq_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     LinkedList<T>
 }
 
 seq_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     Vec<T>
 }
 
 seq_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     VecDeque<T>
 }
 
@@ -371,7 +371,7 @@ impl Serialize for () {
 }
 
 #[cfg(feature = "unstable")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "unstable")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
 impl Serialize for ! {
     fn serialize<S>(&self, _serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -476,13 +476,13 @@ macro_rules! map_impl {
 
 map_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     BTreeMap<K: Ord, V>
 }
 
 map_impl! {
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     HashMap<K: Eq + Hash, V, H: BuildHasher>
 }
 
@@ -516,7 +516,7 @@ deref_impl! {
 
 deref_impl! {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    #[cfg_attr(doc_cfg, doc(cfg(any(feature = "std", feature = "alloc"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     <T> Serialize for Box<T> where T: ?Sized + Serialize
 }
 
@@ -530,7 +530,7 @@ 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")))))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
     <T> Serialize for Rc<T> where T: ?Sized + Serialize
 }
 
@@ -544,13 +544,13 @@ 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")))))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))))]
     <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"))))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
     <'a, T> Serialize for Cow<'a, T> where T: ?Sized + Serialize + ToOwned
 }
 
@@ -561,7 +561,7 @@ deref_impl! {
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 #[cfg_attr(
-    doc_cfg,
+    docsrs,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
 impl<T> Serialize for RcWeak<T>
@@ -581,7 +581,7 @@ where
 /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
 #[cfg_attr(
-    doc_cfg,
+    docsrs,
     doc(cfg(all(feature = "rc", any(feature = "std", feature = "alloc"))))
 )]
 impl<T> Serialize for ArcWeak<T>
@@ -660,7 +660,7 @@ where
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<T> Serialize for Mutex<T>
 where
     T: ?Sized + Serialize,
@@ -677,7 +677,7 @@ where
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<T> Serialize for RwLock<T>
 where
     T: ?Sized + Serialize,
@@ -731,7 +731,7 @@ impl Serialize for Duration {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for SystemTime {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -776,7 +776,7 @@ macro_rules! serialize_display_bounded_length {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for net::IpAddr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -847,7 +847,7 @@ fn test_format_u8() {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for net::Ipv4Addr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -872,7 +872,7 @@ impl Serialize for net::Ipv4Addr {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for net::Ipv6Addr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -889,7 +889,7 @@ impl Serialize for net::Ipv6Addr {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for net::SocketAddr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -914,7 +914,7 @@ impl Serialize for net::SocketAddr {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for net::SocketAddrV4 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -931,7 +931,7 @@ impl Serialize for net::SocketAddrV4 {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for net::SocketAddrV6 {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -953,7 +953,7 @@ impl Serialize for net::SocketAddrV6 {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for Path {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -967,7 +967,7 @@ impl Serialize for Path {
 }
 
 #[cfg(feature = "std")]
-#[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Serialize for PathBuf {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -978,7 +978,7 @@ impl Serialize for PathBuf {
 }
 
 #[cfg(all(feature = "std", any(unix, windows)))]
-#[cfg_attr(doc_cfg, doc(cfg(all(feature = "std", any(unix, windows)))))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
 impl Serialize for OsStr {
     #[cfg(unix)]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -1001,7 +1001,7 @@ impl Serialize for OsStr {
 }
 
 #[cfg(all(feature = "std", any(unix, windows)))]
-#[cfg_attr(doc_cfg, doc(cfg(all(feature = "std", any(unix, windows)))))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "std", any(unix, windows)))))]
 impl Serialize for OsString {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -1060,7 +1060,7 @@ macro_rules! atomic_impl {
     ($($ty:ident $size:expr)*) => {
         $(
             #[cfg(any(no_target_has_atomic, target_has_atomic = $size))]
-            #[cfg_attr(doc_cfg, doc(cfg(all(feature = "std", target_has_atomic = $size))))]
+            #[cfg_attr(docsrs, doc(cfg(all(feature = "std", target_has_atomic = $size))))]
             impl Serialize for $ty {
                 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where