Switch to core::error::Error

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: ['1.79', stable]
+        rust: ['1.81', stable]
     steps:
     - uses: actions/checkout@v4
     - uses: dtolnay/rust-toolchain@master

crates/musli-core/Cargo.toml

@@ -3,7 +3,7 @@ name = "musli-core"
 version = "0.0.123"
 authors = ["John-John Tedro <[email protected]>"]
 edition = "2021"
-rust-version = "1.79"
+rust-version = "1.81"
 description = """
 Core traits and types for the Müsli serialization framework.
 """

crates/musli-core/src/context.rs

@@ -1,11 +1,11 @@
 //! Things related to working with contexts.
 
+use core::error::Error;
 use core::fmt;
 use core::str;
 
 use crate::alloc::Allocator;
 use crate::de::{DecodeBytes, DecodeUnsized, DecodeUnsizedBytes};
-use crate::no_std;
 use crate::{Decode, Decoder};
 
 /// Provides ergonomic access to the serialization context.
@@ -83,7 +83,7 @@ pub trait Context {
     #[inline]
     fn map<T>(&self) -> impl FnOnce(T) -> Self::Error + '_
     where
-        T: 'static + Send + Sync + no_std::Error,
+        T: 'static + Send + Sync + Error,
     {
         move |error| self.custom(error)
     }
@@ -93,7 +93,7 @@ pub trait Context {
     /// reporting error-like things out from the context.
     fn custom<T>(&self, error: T) -> Self::Error
     where
-        T: 'static + Send + Sync + no_std::Error;
+        T: 'static + Send + Sync + Error;
 
     /// Generate a map function which maps an error using the `message` function.
     #[inline]
@@ -131,7 +131,7 @@ pub trait Context {
     #[inline(always)]
     fn marked_custom<T>(&self, mark: Self::Mark, message: T) -> Self::Error
     where
-        T: 'static + Send + Sync + no_std::Error,
+        T: 'static + Send + Sync + Error,
     {
         self.custom(message)
     }

crates/musli-core/src/internal/fixed.rs

@@ -15,8 +15,7 @@ impl fmt::Display for CapacityError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for CapacityError {}
+impl core::error::Error for CapacityError {}
 
 /// A fixed capacity vector allocated on the stack.
 pub(crate) struct FixedVec<T, const N: usize> {

crates/musli-core/src/no_std.rs

@@ -2,35 +2,13 @@
 //!
 //! * [`ToOwned`] - if the `alloc` feature is enabled, this is an alias for
 //!   `alloc::borrow::ToOwned`.
-//! * [`Error`] - if the `std` feature is enabled, this is an alias for
-//!   `std::error::Error`. If the `std` feature is disabled, this is a trait
-//!   which is implemented for everything that implements [`Debug`] and
-//!   [`Display`]. Note that this means that enabling the `std` feature might
-//!   cause code that is designed carelessly to break due to no longer
-//!   implementing the trait.
-//!
-//! [`Debug`]: core::fmt::Debug
-//! [`Display`]: core::fmt::Display
-
-#[cfg(not(feature = "std"))]
-use core::fmt;
 
 #[cfg(feature = "alloc")]
 pub use rust_alloc::borrow::ToOwned;
 
 #[cfg(not(feature = "alloc"))]
 pub use self::to_owned::ToOwned;
 
-#[cfg(feature = "std")]
-pub use std::error::Error;
-
-/// Standard error trait used when the `std` feature is not enabled.
-#[cfg(not(feature = "std"))]
-pub trait Error: fmt::Debug + fmt::Display {}
-
-#[cfg(not(feature = "std"))]
-impl<T> Error for T where T: fmt::Debug + fmt::Display {}
-
 #[cfg(not(feature = "alloc"))]
 mod to_owned {
     use core::borrow::Borrow;

crates/musli-macros/Cargo.toml

@@ -3,7 +3,7 @@ name = "musli-macros"
 version = "0.0.123"
 authors = ["John-John Tedro <[email protected]>"]
 edition = "2021"
-rust-version = "1.79"
+rust-version = "1.81"
 description = """
 Macros for Müsli.
 """

crates/musli-zerocopy-macros/Cargo.toml

@@ -3,7 +3,7 @@ name = "musli-zerocopy-macros"
 version = "0.0.123"
 authors = ["John-John Tedro <[email protected]>"]
 edition = "2021"
-rust-version = "1.79"
+rust-version = "1.81"
 description = """
 Macros for Müsli zero-copy.
 """

crates/musli-zerocopy/Cargo.toml

@@ -3,7 +3,7 @@ name = "musli-zerocopy"
 version = "0.0.123"
 authors = ["John-John Tedro <[email protected]>"]
 edition = "2021"
-rust-version = "1.79"
+rust-version = "1.81"
 description = """
 Refreshingly simple zero copy primitives by Müsli.
 """

crates/musli-zerocopy/src/error.rs

@@ -131,9 +131,8 @@ impl fmt::Display for Error {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {
-    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+impl core::error::Error for Error {
+    fn source(&self) -> Option<&(dyn core::error::Error + 'static)> {
         match &self.kind {
             ErrorKind::Utf8Error { error } => Some(error),
             _ => None,

crates/musli/Cargo.toml

@@ -3,7 +3,7 @@ name = "musli"
 version = "0.0.123"
 authors = ["John-John Tedro <[email protected]>"]
 edition = "2021"
-rust-version = "1.79"
+rust-version = "1.81"
 description = """
 Müsli is a flexible and generic binary serialization framework.
 """

crates/musli/src/context/capture.rs

@@ -1,11 +1,11 @@
 use core::cell::UnsafeCell;
+use core::error::Error;
 use core::fmt;
 use core::marker::PhantomData;
 
 use crate::alloc::{self, Allocator, String};
 #[cfg(feature = "alloc")]
 use crate::alloc::{System, SYSTEM};
-use crate::no_std;
 use crate::Context;
 
 use super::{ContextError, ErrorMarker};
@@ -92,7 +92,7 @@ where
     #[inline]
     fn custom<T>(&self, error: T) -> ErrorMarker
     where
-        T: 'static + Send + Sync + no_std::Error,
+        T: 'static + Send + Sync + Error,
     {
         // SAFETY: We're restricting access to the context, so that this is
         // safe.

crates/musli/src/context/context_error.rs

@@ -5,10 +5,9 @@
 //! encoding implementations to raise custom errors based on types that
 //! implement [Display][core::fmt::Display].
 
+use core::error::Error;
 use core::fmt;
 
-use crate::no_std;
-
 #[cfg(feature = "alloc")]
 use rust_alloc::string::{String, ToString};
 
@@ -22,7 +21,7 @@ pub trait ContextError: Sized + 'static + Send + Sync + fmt::Display + fmt::Debu
     /// Construct a custom error.
     fn custom<T>(error: T) -> Self
     where
-        T: 'static + Send + Sync + no_std::Error;
+        T: 'static + Send + Sync + Error;
 
     /// Collect an error from something that can be displayed.
     ///
@@ -33,20 +32,20 @@ pub trait ContextError: Sized + 'static + Send + Sync + fmt::Display + fmt::Debu
         T: fmt::Display;
 }
 
-#[cfg(all(feature = "std", feature = "alloc"))]
+#[cfg(feature = "std")]
 impl ContextError for std::io::Error {
     fn custom<T>(message: T) -> Self
     where
-        T: 'static + Send + Sync + fmt::Display + fmt::Debug,
+        T: 'static + Send + Sync + Error,
     {
-        std::io::Error::new(std::io::ErrorKind::Other, message.to_string())
+        std::io::Error::new(std::io::ErrorKind::Other, message)
     }
 
     fn message<T>(message: T) -> Self
     where
         T: fmt::Display,
     {
-        std::io::Error::new(std::io::ErrorKind::Other, message.to_string())
+        std::io::Error::new(std::io::ErrorKind::Other, std::format!("{message}"))
     }
 }
 

crates/musli/src/context/error_marker.rs

@@ -17,8 +17,7 @@ impl fmt::Display for ErrorMarker {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for ErrorMarker {}
+impl core::error::Error for ErrorMarker {}
 
 #[cfg(test)]
 impl crate::context::ContextError for ErrorMarker {

crates/musli/src/context/same.rs

@@ -1,3 +1,4 @@
+use core::error::Error;
 use core::fmt;
 use core::marker::PhantomData;
 
@@ -6,7 +7,6 @@ use crate::alloc::{self, Allocator, String};
 use crate::alloc::{System, SYSTEM};
 #[cfg(test)]
 use crate::mode::Binary;
-use crate::no_std;
 use crate::Context;
 
 use super::ContextError;
@@ -90,7 +90,7 @@ where
     #[inline]
     fn custom<T>(&self, message: T) -> Self::Error
     where
-        T: 'static + Send + Sync + no_std::Error,
+        T: 'static + Send + Sync + Error,
     {
         E::custom(message)
     }

crates/musli/src/descriptive/error.rs

@@ -6,7 +6,6 @@ use rust_alloc::boxed::Box;
 use rust_alloc::string::ToString;
 
 use crate::context::ContextError;
-use crate::no_std;
 
 /// Error raised during descriptive encoding.
 #[derive(Debug)]
@@ -26,7 +25,7 @@ enum ErrorImpl {
     #[cfg(feature = "alloc")]
     Message(Box<str>),
     #[cfg(feature = "alloc")]
-    Custom(Box<dyn 'static + Send + Sync + no_std::Error>),
+    Custom(Box<dyn 'static + Send + Sync + core::error::Error>),
     #[cfg(not(feature = "alloc"))]
     Empty,
 }
@@ -44,11 +43,11 @@ impl fmt::Display for ErrorImpl {
     }
 }
 
-#[cfg(all(feature = "std", feature = "alloc"))]
-impl std::error::Error for Error {
+impl core::error::Error for Error {
     #[inline]
-    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+    fn source(&self) -> Option<&(dyn core::error::Error + 'static)> {
         match &self.err {
+            #[cfg(feature = "alloc")]
             ErrorImpl::Custom(err) => Some(&**err),
             _ => None,
         }
@@ -60,7 +59,7 @@ impl ContextError for Error {
     #[allow(unused_variables)]
     fn custom<T>(error: T) -> Self
     where
-        T: 'static + Send + Sync + no_std::Error,
+        T: 'static + Send + Sync + core::error::Error,
     {
         Self {
             #[cfg(feature = "alloc")]

crates/musli/src/json/error.rs

@@ -39,8 +39,7 @@ impl fmt::Display for ErrorImpl {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl ContextError for Error {
     #[inline]
@@ -82,8 +81,7 @@ impl fmt::Display for ErrorMessage {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for ErrorMessage {}
+impl core::error::Error for ErrorMessage {}
 
 #[derive(Debug)]
 #[non_exhaustive]

crates/musli/src/lib.rs

@@ -261,7 +261,7 @@
 //! # struct Version1 { name: String }
 //! # #[derive(Debug, PartialEq, Encode, Decode)]
 //! # struct Version2 { name: String, #[musli(default)] age: Option<u32> }
-//! # fn main() -> Result<(), Box<dyn std::error::Error>> {
+//! # fn main() -> Result<(), Box<dyn core::error::Error>> {
 //! let version2 = musli::storage::to_vec(&Version2 {
 //!     name: String::from("Aristotle"),
 //!     age: Some(61),

crates/musli/src/no_std.rs

@@ -2,18 +2,9 @@
 //!
 //! * [`ToOwned`] - if the `alloc` feature is enabled, this is an alias for
 //!   `alloc::borrow::ToOwned`.
-//! * [`Error`] - if the `std` feature is enabled, this is an alias for
-//!   `std::error::Error`. If the `std` feature is disabled, this is a trait
-//!   which is implemented for everything that implements [`Debug`] and
-//!   [`Display`]. Note that this means that enabling the `std` feature might
-//!   cause code that is designed carelessly to break due to no longer
-//!   implementing the trait.
-//!
-//! [`Debug`]: core::fmt::Debug
-//! [`Display`]: core::fmt::Display
 
 #[doc(inline)]
-pub use musli_core::no_std::{Error, ToOwned};
+pub use musli_core::no_std::ToOwned;
 
 /// A somewhat portable, but also noisy abort implementation for no_std
 /// environments.

crates/musli/src/reader.rs

@@ -603,5 +603,4 @@ impl fmt::Display for SliceUnderflow {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for SliceUnderflow {}
+impl core::error::Error for SliceUnderflow {}

crates/musli/src/serde/mod.rs

@@ -84,7 +84,7 @@
 //! assert_eq!(musli.address.city, "Springfield");
 //! assert_eq!(musli.address.zip, 12345);
 //! assert_eq!(musli.url, "https://example.com/");
-//! # Ok::<_, Box<dyn std::error::Error>>(())
+//! # Ok::<_, Box<dyn core::error::Error>>(())
 //! ```
 
 #![cfg(feature = "serde")]
@@ -95,6 +95,7 @@ mod error;
 mod serializer;
 
 use core::cell::RefCell;
+use core::error::Error;
 use core::fmt;
 
 use serde::{Deserialize, Serialize};
@@ -103,7 +104,6 @@ use self::deserializer::Deserializer;
 use self::serializer::Serializer;
 
 use crate::alloc::{self, String};
-use crate::no_std;
 use crate::{Context, Decoder, Encoder};
 
 struct SerdeContext<'a, C>
@@ -153,7 +153,7 @@ where
     #[inline]
     fn custom<T>(&self, error: T) -> Self::Error
     where
-        T: 'static + Send + Sync + no_std::Error,
+        T: 'static + Send + Sync + Error,
     {
         *self.error.borrow_mut() = Some(self.inner.custom(error));
         error::SerdeError::Captured

crates/musli/src/storage/error.rs

@@ -39,8 +39,7 @@ impl fmt::Display for ErrorImpl {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl ContextError for Error {
     #[inline]