Remove serde::error::Error

serde/src/de/mod.rs

@@ -96,8 +96,6 @@
 
 #[cfg(feature = "std")]
 use std::error;
-#[cfg(not(feature = "std"))]
-use error;
 
 #[cfg(all(not(feature = "std"), feature = "collections"))]
 use collections::{String, Vec};
@@ -123,20 +121,22 @@ pub use self::ignored_any::IgnoredAny;
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// The `Error` trait allows `Deserialize` implementations to create descriptive
+macro_rules! declare_error_trait {
-/// error messages belonging to the `Deserializer` against which they are
+    (Error: Sized $(+ $supertrait:path)*) => {
-/// currently running.
+        /// The `Error` trait allows `Deserialize` implementations to create descriptive
-///
+        /// error messages belonging to the `Deserializer` against which they are
-/// Every `Deserializer` declares an `Error` type that encompasses both
+        /// currently running.
-/// general-purpose deserialization errors as well as errors specific to the
+        ///
-/// particular deserialization format. For example the `Error` type of
+        /// Every `Deserializer` declares an `Error` type that encompasses both
-/// `serde_json` can represent errors like an invalid JSON escape sequence or an
+        /// general-purpose deserialization errors as well as errors specific to the
-/// unterminated string literal, in addition to the error cases that are part of
+        /// particular deserialization format. For example the `Error` type of
-/// this trait.
+        /// `serde_json` can represent errors like an invalid JSON escape sequence or an
-///
+        /// unterminated string literal, in addition to the error cases that are part of
-/// Most deserializers should only need to provide the `Error::custom` method
+        /// this trait.
-/// and inherit the default behavior for the other methods.
+        ///
-pub trait Error: Sized + error::Error {
+        /// Most deserializers should only need to provide the `Error::custom` method
+        /// and inherit the default behavior for the other methods.
+        pub trait Error: Sized $(+ $supertrait)* {
             /// Raised when there is general error when deserializing a type.
             ///
             /// The message should not be capitalized and should not end with a period.
@@ -246,8 +246,16 @@ pub trait Error: Sized + error::Error {
             fn duplicate_field(field: &'static str) -> Self {
                 Error::custom(format_args!("duplicate field `{}`", field))
             }
+        }
+    }
 }
 
+#[cfg(feature = "std")]
+declare_error_trait!(Error: Sized + error::Error);
+
+#[cfg(not(feature = "std"))]
+declare_error_trait!(Error: Sized);
+
 /// `Unexpected` represents an unexpected invocation of any one of the `Visitor`
 /// trait methods.
 ///

serde/src/de/value.rs

@@ -21,8 +21,6 @@ use collections::string::ToString;
 use core::hash::Hash;
 #[cfg(feature = "std")]
 use std::error;
-#[cfg(not(feature = "std"))]
-use error;
 
 use core::fmt::{self, Display};
 use core::iter::{self, Iterator};
@@ -67,16 +65,11 @@ impl Display for Error {
     }
 }
 
+#[cfg(feature = "std")]
 impl error::Error for Error {
-    #[cfg(any(feature = "std", feature = "collections"))]
     fn description(&self) -> &str {
         &self.err
     }
-
-    #[cfg(not(any(feature = "std", feature = "collections")))]
-    fn description(&self) -> &str {
-        "Serde deserialization error"
-    }
 }
 
 ///////////////////////////////////////////////////////////////////////////////

serde/src/error.rs

@@ -1,17 +0,0 @@
-//! A stand-in for `std::error`
-use core::fmt::{Debug, Display};
-
-/// A stand-in for `std::error::Error`, which requires no allocation.
-pub trait Error: Debug + Display {
-    /// A short description of the error.
-    ///
-    /// The description should not contain newlines or sentence-ending
-    /// punctuation, to facilitate embedding in larger user-facing
-    /// strings.
-    fn description(&self) -> &str;
-
-    /// The lower-level cause of this error, if any.
-    fn cause(&self) -> Option<&Error> {
-        None
-    }
-}

serde/src/lib.rs

@@ -98,8 +98,6 @@ pub mod de;
 #[doc(hidden)]
 pub mod iter;
 pub mod ser;
-#[cfg_attr(feature = "std", doc(hidden))]
-pub mod error;
 mod utils;
 
 // Generated code uses these to support no_std. Not public API.

serde/src/ser/mod.rs

@@ -94,8 +94,6 @@
 
 #[cfg(feature = "std")]
 use std::error;
-#[cfg(not(feature = "std"))]
-use error;
 
 #[cfg(all(feature = "collections", not(feature = "std")))]
 use collections::string::String;
@@ -117,16 +115,20 @@ pub use self::impossible::Impossible;
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// Trait used by `Serialize` implementations to generically construct errors
+macro_rules! declare_error_trait {
-/// belonging to the `Serializer` against which they are currently running.
+    (Error: Sized $(+ $supertrait:path)*) => {
-pub trait Error: Sized + error::Error {
+        /// Trait used by `Serialize` implementations to generically construct
-    /// Raised when a `Serialize` implementation encounters a general error
+        /// errors belonging to the `Serializer` against which they are
-    /// while serializing a type.
+        /// currently running.
+        pub trait Error: Sized $(+ $supertrait)* {
+            /// Raised when a `Serialize` implementation encounters a general
+            /// error while serializing a type.
             ///
-    /// The message should not be capitalized and should not end with a period.
+            /// The message should not be capitalized and should not end with a
+            /// period.
             ///
-    /// For example, a filesystem `Path` may refuse to serialize itself if it
+            /// For example, a filesystem `Path` may refuse to serialize itself
-    /// contains invalid UTF-8 data.
+            /// if it contains invalid UTF-8 data.
             ///
             /// ```rust
             /// # use serde::ser::{Serialize, Serializer, Error};
@@ -144,8 +146,16 @@ pub trait Error: Sized + error::Error {
             /// }
             /// ```
             fn custom<T: Display>(msg: T) -> Self;
+        }
+    }
 }
 
+#[cfg(feature = "std")]
+declare_error_trait!(Error: Sized + error::Error);
+
+#[cfg(not(feature = "std"))]
+declare_error_trait!(Error: Sized);
+
 ///////////////////////////////////////////////////////////////////////////////
 
 /// A **data structure** that can be serialized into any data format supported