review: Gate Result impls behind a feature gate

Author: osiewicz

serde/Cargo.toml

@@ -22,10 +22,10 @@ serde_derive = { version = "1", optional = true, path = "../serde_derive" }
 serde_derive = { version = "1", path = "../serde_derive" }
 
 [package.metadata.playground]
-features = ["derive", "rc"]
+features = ["derive", "rc", "result"]
 
 [package.metadata.docs.rs]
-features = ["derive", "rc", "unstable"]
+features = ["derive", "rc", "result", "unstable"]
 targets = ["x86_64-unknown-linux-gnu"]
 rustdoc-args = [
     "--generate-link-to-definition",
@@ -46,7 +46,7 @@ serde_derive = { version = "=1.0.219", path = "../serde_derive" }
 ### FEATURES #################################################################
 
 [features]
-default = ["std"]
+default = ["std", "result"]
 
 # Provide derive(Serialize, Deserialize) macros.
 derive = ["serde_derive"]
@@ -70,3 +70,8 @@ alloc = ["serde_core/alloc"]
 # does not preserve identity and may result in multiple copies of the same data.
 # Be sure that this is what you want before enabling this feature.
 rc = ["serde_core/rc"]
+
+# Provide impls for Result<T, E>. Enabling these impls allows for serialization
+# and deserialization of Result types, which may be useful in certain contexts
+# but could lead to confusion if ? or unwrap are overused.
+result = ["serde_core/result"]

serde_core/Cargo.toml

@@ -18,10 +18,10 @@ rust-version = "1.56"
 serde = { version = "1", path = "../serde" }
 
 [package.metadata.playground]
-features = ["rc"]
+features = ["rc", "result"]
 
 [package.metadata.docs.rs]
-features = ["rc", "unstable"]
+features = ["rc", "result", "unstable"]
 targets = ["x86_64-unknown-linux-gnu"]
 rustdoc-args = [
     "--generate-link-to-definition",
@@ -34,7 +34,7 @@ rustdoc-args = [
 ### FEATURES #################################################################
 
 [features]
-default = ["std"]
+default = ["std", "result"]
 
 # Provide impls for common standard library types like Vec<T> and HashMap<K, V>.
 # Requires a dependency on the Rust standard library.
@@ -55,3 +55,8 @@ alloc = []
 # does not preserve identity and may result in multiple copies of the same data.
 # Be sure that this is what you want before enabling this feature.
 rc = []
+
+# Provide impls for Result<T, E>. Enabling these impls allows for serialization
+# and deserialization of Result types, which may be useful in certain contexts
+# but could lead to confusion if ? or unwrap are overused.
+result = []

serde_core/src/de/impls.rs

@@ -2975,6 +2975,8 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
+#[cfg(feature = "result")]
+#[cfg_attr(docsrs, doc(cfg(feature = "result")))]
 impl<'de, T, E> Deserialize<'de> for Result<T, E>
 where
     T: Deserialize<'de>,

serde_core/src/ser/impls.rs

@@ -660,6 +660,8 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
+#[cfg(feature = "result")]
+#[cfg_attr(docsrs, doc(cfg(feature = "result")))]
 impl<T, E> Serialize for Result<T, E>
 where
     T: Serialize,