Depend on serde_core instead of serde

`time-macro` still emits code that depends on `serde` to avoid a
breaking change.

Author: jhpratt

Cargo.lock

@@ -23,6 +23,7 @@ rstest = { version = "0.23.0", default-features = false }
 rstest_reuse = "0.7.0"
 # ^1.0.184 due to serde-rs/serde#2538
 serde = { version = "1.0.184", default-features = false }
+serde_core = { version = "1.0.220", default-features = false }
 serde_json = "1.0.68"
 serde_test = "1.0.126"
 trybuild = "1.0.102"

Cargo.toml

@@ -31,7 +31,7 @@ rustdoc-args = ["--generate-link-to-definition"]
 
 [features]
 default = ["std"]
-alloc = ["serde?/alloc"]
+alloc = ["serde_core?/alloc"]
 formatting = ["dep:itoa", "std", "time-macros?/formatting"]
 large-dates = ["time-macros?/large-dates"]
 local-offset = ["std", "dep:libc", "dep:num_threads"]
@@ -41,7 +41,7 @@ quickcheck = ["dep:quickcheck", "alloc", "deranged/quickcheck"]
 rand = ["rand08", "rand09"]
 rand08 = ["dep:rand08", "deranged/rand08"]
 rand09 = ["dep:rand09", "deranged/rand09"]
-serde = ["dep:serde", "time-macros?/serde", "deranged/serde"]
+serde = ["dep:serde_core", "time-macros?/serde", "deranged/serde"]
 serde-human-readable = ["serde", "formatting", "parsing"]
 # Deprecated in favor of using the relevant flags directly.
 serde-well-known = ["serde", "formatting", "parsing"]
@@ -58,7 +58,7 @@ powerfmt = { workspace = true }
 quickcheck = { workspace = true, optional = true }
 rand08 = { workspace = true, optional = true }
 rand09 = { workspace = true, optional = true }
-serde = { workspace = true, optional = true }
+serde_core = { workspace = true, optional = true }
 time-core = { workspace = true }
 time-macros = { workspace = true, optional = true }
 

time/Cargo.toml

@@ -99,7 +99,7 @@ impl TryFrom<crate::Error> for ComponentRange {
 
 /// **This trait implementation is deprecated and will be removed in a future breaking release.**
 #[cfg(feature = "serde")]
-impl serde::de::Expected for ComponentRange {
+impl serde_core::de::Expected for ComponentRange {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(
@@ -114,8 +114,8 @@ impl serde::de::Expected for ComponentRange {
 impl ComponentRange {
     /// Convert the error to a deserialization error.
     #[inline]
-    pub(crate) fn into_de_error<E: serde::de::Error>(self) -> E {
-        E::invalid_value(serde::de::Unexpected::Signed(self.value), &self)
+    pub(crate) fn into_de_error<E: serde_core::de::Error>(self) -> E {
+        E::invalid_value(serde_core::de::Unexpected::Signed(self.value), &self)
     }
 }
 

time/src/error/component_range.rs

@@ -114,8 +114,8 @@ impl Format {
     /// Obtain an error type for the serializer.
     #[doc(hidden)] // Exposed only for the `declare_format_string` macro
     #[inline]
-    pub fn into_invalid_serde_value<S: serde::Serializer>(self) -> S::Error {
-        use serde::ser::Error;
+    pub fn into_invalid_serde_value<S: serde_core::Serializer>(self) -> S::Error {
+        use serde_core::ser::Error;
         S::Error::custom(self)
     }
 }

time/src/error/format.rs

@@ -9,11 +9,11 @@
 use core::marker::PhantomData;
 
 #[cfg(feature = "formatting")]
-use serde::ser::Error as _;
+use serde_core::ser::Error as _;
 #[cfg(feature = "parsing")]
-use serde::Deserializer;
+use serde_core::Deserializer;
 #[cfg(feature = "formatting")]
-use serde::{Serialize, Serializer};
+use serde_core::{Serialize, Serializer};
 
 #[cfg(feature = "parsing")]
 use super::Visitor;

time/src/serde/iso8601.rs

@@ -9,7 +9,7 @@
 macro_rules! item {
     ($seq:expr, $name:literal) => {
         $seq.next_element()?
-            .ok_or_else(|| <A::Error as serde::de::Error>::custom(concat!("expected ", $name)))
+            .ok_or_else(|| <A::Error as serde_core::de::Error>::custom(concat!("expected ", $name)))
     };
 }
 
@@ -27,8 +27,8 @@ use alloc::string::ToString;
 use core::marker::PhantomData;
 
 #[cfg(feature = "serde-human-readable")]
-use serde::ser::Error as _;
-use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use serde_core::ser::Error as _;
+use serde_core::{Deserialize, Deserializer, Serialize, Serializer};
 /// Generate a custom serializer and deserializer from a format string or an existing format.
 ///
 /// The syntax accepted by this macro is the same as [`format_description::parse()`], which can

time/src/serde/mod.rs

@@ -9,11 +9,11 @@
 use core::marker::PhantomData;
 
 #[cfg(feature = "formatting")]
-use serde::ser::Error as _;
+use serde_core::ser::Error as _;
 #[cfg(feature = "parsing")]
-use serde::Deserializer;
+use serde_core::Deserializer;
 #[cfg(feature = "formatting")]
-use serde::{Serialize, Serializer};
+use serde_core::{Serialize, Serializer};
 
 #[cfg(feature = "parsing")]
 use super::Visitor;

time/src/serde/rfc2822.rs

@@ -9,11 +9,11 @@
 use core::marker::PhantomData;
 
 #[cfg(feature = "formatting")]
-use serde::ser::Error as _;
+use serde_core::ser::Error as _;
 #[cfg(feature = "parsing")]
-use serde::Deserializer;
+use serde_core::Deserializer;
 #[cfg(feature = "formatting")]
-use serde::{Serialize, Serializer};
+use serde_core::{Serialize, Serializer};
 
 #[cfg(feature = "parsing")]
 use super::Visitor;

time/src/serde/rfc3339.rs

@@ -8,7 +8,7 @@
 //! [Unix timestamp]: https://en.wikipedia.org/wiki/Unix_time
 //! [with]: https://serde.rs/field-attrs.html#with
 
-use serde::{de, Deserialize, Deserializer, Serialize, Serializer};
+use serde_core::{de, Deserialize, Deserializer, Serialize, Serializer};
 
 use crate::OffsetDateTime;