Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

vendor/serde/src/de/format.rs

@@ -0,0 +1,30 @@
+use crate::lib::fmt::{self, Write};
+use crate::lib::str;
+
+pub(super) struct Buf<'a> {
+    bytes: &'a mut [u8],
+    offset: usize,
+}
+
+impl<'a> Buf<'a> {
+    pub fn new(bytes: &'a mut [u8]) -> Self {
+        Buf { bytes, offset: 0 }
+    }
+
+    pub fn as_str(&self) -> &str {
+        let slice = &self.bytes[..self.offset];
+        unsafe { str::from_utf8_unchecked(slice) }
+    }
+}
+
+impl<'a> Write for Buf<'a> {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        if self.offset + s.len() > self.bytes.len() {
+            Err(fmt::Error)
+        } else {
+            self.bytes[self.offset..self.offset + s.len()].copy_from_slice(s.as_bytes());
+            self.offset += s.len();
+            Ok(())
+        }
+    }
+}

vendor/serde/src/de/ignored_any.rs

@@ -0,0 +1,238 @@
+use crate::lib::*;
+
+use crate::de::{
+    Deserialize, Deserializer, EnumAccess, Error, MapAccess, SeqAccess, VariantAccess, Visitor,
+};
+
+/// An efficient way of discarding data from a deserializer.
+///
+/// Think of this like `serde_json::Value` in that it can be deserialized from
+/// any type, except that it does not store any information about the data that
+/// gets deserialized.
+///
+/// ```edition2021
+/// use serde::de::{
+///     self, Deserialize, DeserializeSeed, Deserializer, IgnoredAny, SeqAccess, Visitor,
+/// };
+/// use std::fmt;
+/// use std::marker::PhantomData;
+///
+/// /// A seed that can be used to deserialize only the `n`th element of a sequence
+/// /// while efficiently discarding elements of any type before or after index `n`.
+/// ///
+/// /// For example to deserialize only the element at index 3:
+/// ///
+/// /// ```
+/// /// NthElement::new(3).deserialize(deserializer)
+/// /// ```
+/// pub struct NthElement<T> {
+///     n: usize,
+///     marker: PhantomData<T>,
+/// }
+///
+/// impl<T> NthElement<T> {
+///     pub fn new(n: usize) -> Self {
+///         NthElement {
+///             n: n,
+///             marker: PhantomData,
+///         }
+///     }
+/// }
+///
+/// impl<'de, T> Visitor<'de> for NthElement<T>
+/// where
+///     T: Deserialize<'de>,
+/// {
+///     type Value = T;
+///
+///     fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+///         write!(
+///             formatter,
+///             "a sequence in which we care about element {}",
+///             self.n
+///         )
+///     }
+///
+///     fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+///     where
+///         A: SeqAccess<'de>,
+///     {
+///         // Skip over the first `n` elements.
+///         for i in 0..self.n {
+///             // It is an error if the sequence ends before we get to element `n`.
+///             if seq.next_element::<IgnoredAny>()?.is_none() {
+///                 return Err(de::Error::invalid_length(i, &self));
+///             }
+///         }
+///
+///         // Deserialize the one we care about.
+///         let nth = match seq.next_element()? {
+///             Some(nth) => nth,
+///             None => {
+///                 return Err(de::Error::invalid_length(self.n, &self));
+///             }
+///         };
+///
+///         // Skip over any remaining elements in the sequence after `n`.
+///         while let Some(IgnoredAny) = seq.next_element()? {
+///             // ignore
+///         }
+///
+///         Ok(nth)
+///     }
+/// }
+///
+/// impl<'de, T> DeserializeSeed<'de> for NthElement<T>
+/// where
+///     T: Deserialize<'de>,
+/// {
+///     type Value = T;
+///
+///     fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+///     where
+///         D: Deserializer<'de>,
+///     {
+///         deserializer.deserialize_seq(self)
+///     }
+/// }
+///
+/// # fn example<'de, D>(deserializer: D) -> Result<(), D::Error>
+/// # where
+/// #     D: Deserializer<'de>,
+/// # {
+/// // Deserialize only the sequence element at index 3 from this deserializer.
+/// // The element at index 3 is required to be a string. Elements before and
+/// // after index 3 are allowed to be of any type.
+/// let s: String = NthElement::new(3).deserialize(deserializer)?;
+/// #     Ok(())
+/// # }
+/// ```
+#[derive(Copy, Clone, Debug, Default, PartialEq)]
+pub struct IgnoredAny;
+
+impl<'de> Visitor<'de> for IgnoredAny {
+    type Value = IgnoredAny;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("anything at all")
+    }
+
+    #[inline]
+    fn visit_bool<E>(self, x: bool) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_i64<E>(self, x: i64) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_i128<E>(self, x: i128) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_u64<E>(self, x: u64) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_u128<E>(self, x: u128) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_f64<E>(self, x: f64) -> Result<Self::Value, E> {
+        let _ = x;
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        let _ = s;
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_none<E>(self) -> Result<Self::Value, E> {
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        IgnoredAny::deserialize(deserializer)
+    }
+
+    #[inline]
+    fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        IgnoredAny::deserialize(deserializer)
+    }
+
+    #[inline]
+    fn visit_unit<E>(self) -> Result<Self::Value, E> {
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+    where
+        A: SeqAccess<'de>,
+    {
+        while let Some(IgnoredAny) = tri!(seq.next_element()) {
+            // Gobble
+        }
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+    where
+        A: MapAccess<'de>,
+    {
+        while let Some((IgnoredAny, IgnoredAny)) = tri!(map.next_entry()) {
+            // Gobble
+        }
+        Ok(IgnoredAny)
+    }
+
+    #[inline]
+    fn visit_bytes<E>(self, bytes: &[u8]) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        let _ = bytes;
+        Ok(IgnoredAny)
+    }
+
+    fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error>
+    where
+        A: EnumAccess<'de>,
+    {
+        tri!(data.variant::<IgnoredAny>()).1.newtype_variant()
+    }
+}
+
+impl<'de> Deserialize<'de> for IgnoredAny {
+    #[inline]
+    fn deserialize<D>(deserializer: D) -> Result<IgnoredAny, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_ignored_any(IgnoredAny)
+    }
+}

vendor/serde/src/de/seed.rs

@@ -0,0 +1,19 @@
+use crate::de::{Deserialize, DeserializeSeed, Deserializer};
+
+/// A DeserializeSeed helper for implementing deserialize_in_place Visitors.
+///
+/// Wraps a mutable reference and calls deserialize_in_place on it.
+pub struct InPlaceSeed<'a, T: 'a>(pub &'a mut T);
+
+impl<'a, 'de, T> DeserializeSeed<'de> for InPlaceSeed<'a, T>
+where
+    T: Deserialize<'de>,
+{
+    type Value = ();
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        T::deserialize_in_place(deserializer, self.0)
+    }
+}

vendor/serde/src/de/size_hint.rs

@@ -0,0 +1,29 @@
+use crate::lib::*;
+
+pub fn from_bounds<I>(iter: &I) -> Option<usize>
+where
+    I: Iterator,
+{
+    helper(iter.size_hint())
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub fn cautious<Element>(hint: Option<usize>) -> usize {
+    const MAX_PREALLOC_BYTES: usize = 1024 * 1024;
+
+    if mem::size_of::<Element>() == 0 {
+        0
+    } else {
+        cmp::min(
+            hint.unwrap_or(0),
+            MAX_PREALLOC_BYTES / mem::size_of::<Element>(),
+        )
+    }
+}
+
+fn helper(bounds: (usize, Option<usize>)) -> Option<usize> {
+    match bounds {
+        (lower, Some(upper)) if lower == upper => Some(upper),
+        _ => None,
+    }
+}

vendor/serde/src/integer128.rs

@@ -0,0 +1,9 @@
+// No longer used. Old versions of serde used this macro for supporting targets
+// that did not yet have 128-bit integer support.
+#[macro_export]
+#[doc(hidden)]
+macro_rules! serde_if_integer128 {
+    ($($tt:tt)*) => {
+        $($tt)*
+    };
+}

vendor/serde/src/lib.rs

@@ -0,0 +1,334 @@
+//! # Serde
+//!
+//! Serde is a framework for ***ser***ializing and ***de***serializing Rust data
+//! structures efficiently and generically.
+//!
+//! The Serde ecosystem consists of data structures that know how to serialize
+//! and deserialize themselves along with data formats that know how to
+//! serialize and deserialize other things. Serde provides the layer by which
+//! these two groups interact with each other, allowing any supported data
+//! structure to be serialized and deserialized using any supported data format.
+//!
+//! See the Serde website <https://serde.rs/> for additional documentation and
+//! usage examples.
+//!
+//! ## Design
+//!
+//! Where many other languages rely on runtime reflection for serializing data,
+//! Serde is instead built on Rust's powerful trait system. A data structure
+//! that knows how to serialize and deserialize itself is one that implements
+//! Serde's `Serialize` and `Deserialize` traits (or uses Serde's derive
+//! attribute to automatically generate implementations at compile time). This
+//! avoids any overhead of reflection or runtime type information. In fact in
+//! many situations the interaction between data structure and data format can
+//! be completely optimized away by the Rust compiler, leaving Serde
+//! serialization to perform the same speed as a handwritten serializer for the
+//! specific selection of data structure and data format.
+//!
+//! ## Data formats
+//!
+//! The following is a partial list of data formats that have been implemented
+//! for Serde by the community.
+//!
+//! - [JSON], the ubiquitous JavaScript Object Notation used by many HTTP APIs.
+//! - [Postcard], a no\_std and embedded-systems friendly compact binary format.
+//! - [CBOR], a Concise Binary Object Representation designed for small message
+//!   size without the need for version negotiation.
+//! - [YAML], a self-proclaimed human-friendly configuration language that ain't
+//!   markup language.
+//! - [MessagePack], an efficient binary format that resembles a compact JSON.
+//! - [TOML], a minimal configuration format used by [Cargo].
+//! - [Pickle], a format common in the Python world.
+//! - [RON], a Rusty Object Notation.
+//! - [BSON], the data storage and network transfer format used by MongoDB.
+//! - [Avro], a binary format used within Apache Hadoop, with support for schema
+//!   definition.
+//! - [JSON5], a superset of JSON including some productions from ES5.
+//! - [URL] query strings, in the x-www-form-urlencoded format.
+//! - [Starlark], the format used for describing build targets by the Bazel and
+//!   Buck build systems. *(serialization only)*
+//! - [Envy], a way to deserialize environment variables into Rust structs.
+//!   *(deserialization only)*
+//! - [Envy Store], a way to deserialize [AWS Parameter Store] parameters into
+//!   Rust structs. *(deserialization only)*
+//! - [S-expressions], the textual representation of code and data used by the
+//!   Lisp language family.
+//! - [D-Bus]'s binary wire format.
+//! - [FlexBuffers], the schemaless cousin of Google's FlatBuffers zero-copy
+//!   serialization format.
+//! - [Bencode], a simple binary format used in the BitTorrent protocol.
+//! - [Token streams], for processing Rust procedural macro input.
+//!   *(deserialization only)*
+//! - [DynamoDB Items], the format used by [rusoto_dynamodb] to transfer data to
+//!   and from DynamoDB.
+//! - [Hjson], a syntax extension to JSON designed around human reading and
+//!   editing. *(deserialization only)*
+//! - [CSV], Comma-separated values is a tabular text file format.
+//!
+//! [JSON]: https://github.com/serde-rs/json
+//! [Postcard]: https://github.com/jamesmunns/postcard
+//! [CBOR]: https://github.com/enarx/ciborium
+//! [YAML]: https://github.com/dtolnay/serde-yaml
+//! [MessagePack]: https://github.com/3Hren/msgpack-rust
+//! [TOML]: https://docs.rs/toml
+//! [Pickle]: https://github.com/birkenfeld/serde-pickle
+//! [RON]: https://github.com/ron-rs/ron
+//! [BSON]: https://github.com/mongodb/bson-rust
+//! [Avro]: https://docs.rs/apache-avro
+//! [JSON5]: https://github.com/callum-oakley/json5-rs
+//! [URL]: https://docs.rs/serde_qs
+//! [Starlark]: https://github.com/dtolnay/serde-starlark
+//! [Envy]: https://github.com/softprops/envy
+//! [Envy Store]: https://github.com/softprops/envy-store
+//! [Cargo]: https://doc.rust-lang.org/cargo/reference/manifest.html
+//! [AWS Parameter Store]: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-parameter-store.html
+//! [S-expressions]: https://github.com/rotty/lexpr-rs
+//! [D-Bus]: https://docs.rs/zvariant
+//! [FlexBuffers]: https://github.com/google/flatbuffers/tree/master/rust/flexbuffers
+//! [Bencode]: https://github.com/P3KI/bendy
+//! [Token streams]: https://github.com/oxidecomputer/serde_tokenstream
+//! [DynamoDB Items]: https://docs.rs/serde_dynamo
+//! [rusoto_dynamodb]: https://docs.rs/rusoto_dynamodb
+//! [Hjson]: https://github.com/Canop/deser-hjson
+//! [CSV]: https://docs.rs/csv
+
+////////////////////////////////////////////////////////////////////////////////
+
+// Serde types in rustdoc of other crates get linked to here.
+#![doc(html_root_url = "https://docs.rs/serde/1.0.195")]
+// 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))]
+// Unstable functionality only if the user asks for it. For tracking and
+// discussion of these features please refer to this issue:
+//
+//    https://github.com/serde-rs/serde/issues/812
+#![cfg_attr(feature = "unstable", feature(error_in_core, never_type))]
+#![allow(unknown_lints, bare_trait_objects, deprecated)]
+// Ignored clippy and clippy_pedantic lints
+#![allow(
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+    clippy::unnested_or_patterns,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/7768
+    clippy::semicolon_if_nothing_returned,
+    // not available in our oldest supported compiler
+    clippy::empty_enum,
+    clippy::type_repetition_in_bounds, // https://github.com/rust-lang/rust-clippy/issues/8772
+    // integer and float ser/de requires these sorts of casts
+    clippy::cast_possible_truncation,
+    clippy::cast_possible_wrap,
+    clippy::cast_sign_loss,
+    // things are often more readable this way
+    clippy::cast_lossless,
+    clippy::module_name_repetitions,
+    clippy::single_match_else,
+    clippy::type_complexity,
+    clippy::use_self,
+    clippy::zero_prefixed_literal,
+    // correctly used
+    clippy::derive_partial_eq_without_eq,
+    clippy::enum_glob_use,
+    clippy::explicit_auto_deref,
+    clippy::let_underscore_untyped,
+    clippy::map_err_ignore,
+    clippy::new_without_default,
+    clippy::result_unit_err,
+    clippy::wildcard_imports,
+    // not practical
+    clippy::needless_pass_by_value,
+    clippy::similar_names,
+    clippy::too_many_lines,
+    // preference
+    clippy::doc_markdown,
+    clippy::unseparated_literal_suffix,
+    // false positive
+    clippy::needless_doctest_main,
+    // noisy
+    clippy::missing_errors_doc,
+    clippy::must_use_candidate,
+)]
+// Restrictions
+#![deny(clippy::question_mark_used)]
+// Rustc lints.
+#![deny(missing_docs, unused_imports)]
+
+////////////////////////////////////////////////////////////////////////////////
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+/// A facade around all the types we need from the `std`, `core`, and `alloc`
+/// crates. This avoids elaborate import wrangling having to happen in every
+/// module.
+mod lib {
+    mod core {
+        #[cfg(not(feature = "std"))]
+        pub use core::*;
+        #[cfg(feature = "std")]
+        pub use std::*;
+    }
+
+    pub use self::core::{f32, f64};
+    pub use self::core::{i16, i32, i64, i8, isize};
+    pub use self::core::{iter, num, ptr, str};
+    pub use self::core::{u16, u32, u64, u8, usize};
+
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    pub use self::core::{cmp, mem, slice};
+
+    pub use self::core::cell::{Cell, RefCell};
+    pub use self::core::clone::{self, Clone};
+    pub use self::core::cmp::Reverse;
+    pub use self::core::convert::{self, From, Into};
+    pub use self::core::default::{self, Default};
+    pub use self::core::fmt::{self, Debug, Display};
+    pub use self::core::marker::{self, PhantomData};
+    pub use self::core::num::Wrapping;
+    pub use self::core::ops::{Bound, Range, RangeFrom, RangeInclusive, RangeTo};
+    pub use self::core::option::{self, Option};
+    pub use self::core::result::{self, Result};
+    pub use self::core::time::Duration;
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::borrow::{Cow, ToOwned};
+    #[cfg(feature = "std")]
+    pub use std::borrow::{Cow, ToOwned};
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::string::{String, ToString};
+    #[cfg(feature = "std")]
+    pub use std::string::{String, ToString};
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::vec::Vec;
+    #[cfg(feature = "std")]
+    pub use std::vec::Vec;
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::boxed::Box;
+    #[cfg(feature = "std")]
+    pub use std::boxed::Box;
+
+    #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
+    pub use alloc::rc::{Rc, Weak as RcWeak};
+    #[cfg(all(feature = "rc", feature = "std"))]
+    pub use std::rc::{Rc, Weak as RcWeak};
+
+    #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
+    pub use alloc::sync::{Arc, Weak as ArcWeak};
+    #[cfg(all(feature = "rc", feature = "std"))]
+    pub use std::sync::{Arc, Weak as ArcWeak};
+
+    #[cfg(all(feature = "alloc", not(feature = "std")))]
+    pub use alloc::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
+    #[cfg(feature = "std")]
+    pub use std::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
+
+    #[cfg(all(not(no_core_cstr), not(feature = "std")))]
+    pub use self::core::ffi::CStr;
+    #[cfg(feature = "std")]
+    pub use std::ffi::CStr;
+
+    #[cfg(all(not(no_core_cstr), feature = "alloc", not(feature = "std")))]
+    pub use alloc::ffi::CString;
+    #[cfg(feature = "std")]
+    pub use std::ffi::CString;
+
+    #[cfg(feature = "std")]
+    pub use std::{error, net};
+
+    #[cfg(feature = "std")]
+    pub use std::collections::{HashMap, HashSet};
+    #[cfg(feature = "std")]
+    pub use std::ffi::{OsStr, OsString};
+    #[cfg(feature = "std")]
+    pub use std::hash::{BuildHasher, Hash};
+    #[cfg(feature = "std")]
+    pub use std::io::Write;
+    #[cfg(feature = "std")]
+    pub use std::path::{Path, PathBuf};
+    #[cfg(feature = "std")]
+    pub use std::sync::{Mutex, RwLock};
+    #[cfg(feature = "std")]
+    pub use std::time::{SystemTime, UNIX_EPOCH};
+
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic)))]
+    pub use std::sync::atomic::{
+        AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
+        AtomicUsize, Ordering,
+    };
+    #[cfg(all(feature = "std", no_target_has_atomic, not(no_std_atomic64)))]
+    pub use std::sync::atomic::{AtomicI64, AtomicU64};
+
+    #[cfg(all(feature = "std", not(no_target_has_atomic)))]
+    pub use std::sync::atomic::Ordering;
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "8"))]
+    pub use std::sync::atomic::{AtomicBool, AtomicI8, AtomicU8};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "16"))]
+    pub use std::sync::atomic::{AtomicI16, AtomicU16};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "32"))]
+    pub use std::sync::atomic::{AtomicI32, AtomicU32};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "64"))]
+    pub use std::sync::atomic::{AtomicI64, AtomicU64};
+    #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "ptr"))]
+    pub use std::sync::atomic::{AtomicIsize, AtomicUsize};
+}
+
+// None of this crate's error handling needs the `From::from` error conversion
+// performed implicitly by the `?` operator or the standard library's `try!`
+// macro. This simplified macro gives a 5.5% improvement in compile time
+// compared to standard `try!`, and 9% improvement compared to `?`.
+macro_rules! tri {
+    ($expr:expr) => {
+        match $expr {
+            Ok(val) => val,
+            Err(err) => return Err(err),
+        }
+    };
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#[macro_use]
+mod macros;
+
+#[macro_use]
+mod integer128;
+
+pub mod de;
+pub mod ser;
+
+#[doc(inline)]
+pub use crate::de::{Deserialize, Deserializer};
+#[doc(inline)]
+pub use crate::ser::{Serialize, Serializer};
+
+// Used by generated code and doc tests. Not public API.
+#[doc(hidden)]
+#[path = "private/mod.rs"]
+pub mod __private;
+
+#[path = "de/seed.rs"]
+mod seed;
+
+#[cfg(not(any(feature = "std", feature = "unstable")))]
+mod std_error;
+
+// Re-export #[derive(Serialize, Deserialize)].
+//
+// The reason re-exporting is not enabled by default is that disabling it would
+// be annoying for crates that provide handwritten impls or data formats. They
+// would need to disable default features and then explicitly re-enable std.
+#[cfg(feature = "serde_derive")]
+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")))]
+pub use serde_derive::{Deserialize, Serialize};
+
+#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+mod actually_private {
+    pub struct T;
+}

vendor/serde/src/macros.rs

@@ -0,0 +1,231 @@
+// Super explicit first paragraph because this shows up at the top level and
+// trips up people who are just looking for basic Serialize / Deserialize
+// documentation.
+//
+/// Helper macro when implementing the `Deserializer` part of a new data format
+/// for Serde.
+///
+/// Some [`Deserializer`] implementations for self-describing formats do not
+/// care what hint the [`Visitor`] gives them, they just want to blindly call
+/// the [`Visitor`] method corresponding to the data they can tell is in the
+/// input. This requires repetitive implementations of all the [`Deserializer`]
+/// trait methods.
+///
+/// ```edition2021
+/// # use serde::forward_to_deserialize_any;
+/// # use serde::de::{value, Deserializer, Visitor};
+/// #
+/// # struct MyDeserializer;
+/// #
+/// # impl<'de> Deserializer<'de> for MyDeserializer {
+/// #     type Error = value::Error;
+/// #
+/// #     fn deserialize_any<V>(self, _: V) -> Result<V::Value, Self::Error>
+/// #     where
+/// #         V: Visitor<'de>,
+/// #     {
+/// #         unimplemented!()
+/// #     }
+/// #
+/// #[inline]
+/// fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+/// where
+///     V: Visitor<'de>,
+/// {
+///     self.deserialize_any(visitor)
+/// }
+/// #
+/// #     forward_to_deserialize_any! {
+/// #         i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+/// #         bytes byte_buf option unit unit_struct newtype_struct seq tuple
+/// #         tuple_struct map struct enum identifier ignored_any
+/// #     }
+/// # }
+/// ```
+///
+/// The `forward_to_deserialize_any!` macro implements these simple forwarding
+/// methods so that they forward directly to [`Deserializer::deserialize_any`].
+/// You can choose which methods to forward.
+///
+/// ```edition2021
+/// # use serde::forward_to_deserialize_any;
+/// # use serde::de::{value, Deserializer, Visitor};
+/// #
+/// # struct MyDeserializer;
+/// #
+/// impl<'de> Deserializer<'de> for MyDeserializer {
+/// #   type Error = value::Error;
+/// #
+///     fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+///     where
+///         V: Visitor<'de>,
+///     {
+///         /* ... */
+/// #       let _ = visitor;
+/// #       unimplemented!()
+///     }
+///
+///     forward_to_deserialize_any! {
+///         bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+///         bytes byte_buf option unit unit_struct newtype_struct seq tuple
+///         tuple_struct map struct enum identifier ignored_any
+///     }
+/// }
+/// ```
+///
+/// The macro assumes the convention that your `Deserializer` lifetime parameter
+/// is called `'de` and that the `Visitor` type parameters on each method are
+/// called `V`. A different type parameter and a different lifetime can be
+/// specified explicitly if necessary.
+///
+/// ```edition2021
+/// # use serde::forward_to_deserialize_any;
+/// # use serde::de::{value, Deserializer, Visitor};
+/// # use std::marker::PhantomData;
+/// #
+/// # struct MyDeserializer<V>(PhantomData<V>);
+/// #
+/// # impl<'q, V> Deserializer<'q> for MyDeserializer<V> {
+/// #     type Error = value::Error;
+/// #
+/// #     fn deserialize_any<W>(self, visitor: W) -> Result<W::Value, Self::Error>
+/// #     where
+/// #         W: Visitor<'q>,
+/// #     {
+/// #         unimplemented!()
+/// #     }
+/// #
+/// forward_to_deserialize_any! {
+///     <W: Visitor<'q>>
+///     bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+///     bytes byte_buf option unit unit_struct newtype_struct seq tuple
+///     tuple_struct map struct enum identifier ignored_any
+/// }
+/// # }
+/// ```
+///
+/// [`Deserializer`]: trait.Deserializer.html
+/// [`Visitor`]: de/trait.Visitor.html
+/// [`Deserializer::deserialize_any`]: trait.Deserializer.html#tymethod.deserialize_any
+#[macro_export(local_inner_macros)]
+macro_rules! forward_to_deserialize_any {
+    (<$visitor:ident: Visitor<$lifetime:tt>> $($func:ident)*) => {
+        $(forward_to_deserialize_any_helper!{$func<$lifetime, $visitor>})*
+    };
+    // This case must be after the previous one.
+    ($($func:ident)*) => {
+        $(forward_to_deserialize_any_helper!{$func<'de, V>})*
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! forward_to_deserialize_any_method {
+    ($func:ident<$l:tt, $v:ident>($($arg:ident : $ty:ty),*)) => {
+        #[inline]
+        fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::__private::Result<$v::Value, Self::Error>
+        where
+            $v: $crate::de::Visitor<$l>,
+        {
+            $(
+                let _ = $arg;
+            )*
+            self.deserialize_any(visitor)
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export(local_inner_macros)]
+macro_rules! forward_to_deserialize_any_helper {
+    (bool<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_bool<$l, $v>()}
+    };
+    (i8<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_i8<$l, $v>()}
+    };
+    (i16<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_i16<$l, $v>()}
+    };
+    (i32<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_i32<$l, $v>()}
+    };
+    (i64<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_i64<$l, $v>()}
+    };
+    (i128<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_i128<$l, $v>()}
+    };
+    (u8<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_u8<$l, $v>()}
+    };
+    (u16<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_u16<$l, $v>()}
+    };
+    (u32<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_u32<$l, $v>()}
+    };
+    (u64<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_u64<$l, $v>()}
+    };
+    (u128<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_u128<$l, $v>()}
+    };
+    (f32<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_f32<$l, $v>()}
+    };
+    (f64<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_f64<$l, $v>()}
+    };
+    (char<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_char<$l, $v>()}
+    };
+    (str<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_str<$l, $v>()}
+    };
+    (string<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_string<$l, $v>()}
+    };
+    (bytes<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_bytes<$l, $v>()}
+    };
+    (byte_buf<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_byte_buf<$l, $v>()}
+    };
+    (option<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_option<$l, $v>()}
+    };
+    (unit<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_unit<$l, $v>()}
+    };
+    (unit_struct<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_unit_struct<$l, $v>(name: &'static str)}
+    };
+    (newtype_struct<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_newtype_struct<$l, $v>(name: &'static str)}
+    };
+    (seq<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_seq<$l, $v>()}
+    };
+    (tuple<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_tuple<$l, $v>(len: usize)}
+    };
+    (tuple_struct<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_tuple_struct<$l, $v>(name: &'static str, len: usize)}
+    };
+    (map<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_map<$l, $v>()}
+    };
+    (struct<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_struct<$l, $v>(name: &'static str, fields: &'static [&'static str])}
+    };
+    (enum<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_enum<$l, $v>(name: &'static str, variants: &'static [&'static str])}
+    };
+    (identifier<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_identifier<$l, $v>()}
+    };
+    (ignored_any<$l:tt, $v:ident>) => {
+        forward_to_deserialize_any_method!{deserialize_ignored_any<$l, $v>()}
+    };
+}

vendor/serde/src/private/doc.rs

@@ -0,0 +1,159 @@
+// Used only by Serde doc tests. Not public API.
+
+use crate::lib::*;
+
+use crate::ser;
+
+#[doc(hidden)]
+#[derive(Debug)]
+pub struct Error;
+
+impl ser::Error for Error {
+    fn custom<T>(_: T) -> Self
+    where
+        T: Display,
+    {
+        unimplemented!()
+    }
+}
+
+#[cfg(feature = "std")]
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        unimplemented!()
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
+        unimplemented!()
+    }
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __private_serialize {
+    () => {
+        trait Serialize {
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+            where
+                S: $crate::Serializer;
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export(local_inner_macros)]
+macro_rules! __serialize_unimplemented {
+    ($($func:ident)*) => {
+        $(
+            __serialize_unimplemented_helper!($func);
+        )*
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __serialize_unimplemented_method {
+    ($func:ident $(<$t:ident>)* ($($arg:ty),*) -> $ret:ident) => {
+        fn $func $(<$t: ?Sized + $crate::Serialize>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error> {
+            unimplemented!()
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export(local_inner_macros)]
+macro_rules! __serialize_unimplemented_helper {
+    (bool) => {
+        __serialize_unimplemented_method!(serialize_bool(bool) -> Ok);
+    };
+    (i8) => {
+        __serialize_unimplemented_method!(serialize_i8(i8) -> Ok);
+    };
+    (i16) => {
+        __serialize_unimplemented_method!(serialize_i16(i16) -> Ok);
+    };
+    (i32) => {
+        __serialize_unimplemented_method!(serialize_i32(i32) -> Ok);
+    };
+    (i64) => {
+        __serialize_unimplemented_method!(serialize_i64(i64) -> Ok);
+    };
+    (u8) => {
+        __serialize_unimplemented_method!(serialize_u8(u8) -> Ok);
+    };
+    (u16) => {
+        __serialize_unimplemented_method!(serialize_u16(u16) -> Ok);
+    };
+    (u32) => {
+        __serialize_unimplemented_method!(serialize_u32(u32) -> Ok);
+    };
+    (u64) => {
+        __serialize_unimplemented_method!(serialize_u64(u64) -> Ok);
+    };
+    (f32) => {
+        __serialize_unimplemented_method!(serialize_f32(f32) -> Ok);
+    };
+    (f64) => {
+        __serialize_unimplemented_method!(serialize_f64(f64) -> Ok);
+    };
+    (char) => {
+        __serialize_unimplemented_method!(serialize_char(char) -> Ok);
+    };
+    (str) => {
+        __serialize_unimplemented_method!(serialize_str(&str) -> Ok);
+    };
+    (bytes) => {
+        __serialize_unimplemented_method!(serialize_bytes(&[u8]) -> Ok);
+    };
+    (none) => {
+        __serialize_unimplemented_method!(serialize_none() -> Ok);
+    };
+    (some) => {
+        __serialize_unimplemented_method!(serialize_some<T>(&T) -> Ok);
+    };
+    (unit) => {
+        __serialize_unimplemented_method!(serialize_unit() -> Ok);
+    };
+    (unit_struct) => {
+        __serialize_unimplemented_method!(serialize_unit_struct(&str) -> Ok);
+    };
+    (unit_variant) => {
+        __serialize_unimplemented_method!(serialize_unit_variant(&str, u32, &str) -> Ok);
+    };
+    (newtype_struct) => {
+        __serialize_unimplemented_method!(serialize_newtype_struct<T>(&str, &T) -> Ok);
+    };
+    (newtype_variant) => {
+        __serialize_unimplemented_method!(serialize_newtype_variant<T>(&str, u32, &str, &T) -> Ok);
+    };
+    (seq) => {
+        type SerializeSeq = $crate::ser::Impossible<Self::Ok, Self::Error>;
+        __serialize_unimplemented_method!(serialize_seq(Option<usize>) -> SerializeSeq);
+    };
+    (tuple) => {
+        type SerializeTuple = $crate::ser::Impossible<Self::Ok, Self::Error>;
+        __serialize_unimplemented_method!(serialize_tuple(usize) -> SerializeTuple);
+    };
+    (tuple_struct) => {
+        type SerializeTupleStruct = $crate::ser::Impossible<Self::Ok, Self::Error>;
+        __serialize_unimplemented_method!(serialize_tuple_struct(&str, usize) -> SerializeTupleStruct);
+    };
+    (tuple_variant) => {
+        type SerializeTupleVariant = $crate::ser::Impossible<Self::Ok, Self::Error>;
+        __serialize_unimplemented_method!(serialize_tuple_variant(&str, u32, &str, usize) -> SerializeTupleVariant);
+    };
+    (map) => {
+        type SerializeMap = $crate::ser::Impossible<Self::Ok, Self::Error>;
+        __serialize_unimplemented_method!(serialize_map(Option<usize>) -> SerializeMap);
+    };
+    (struct) => {
+        type SerializeStruct = $crate::ser::Impossible<Self::Ok, Self::Error>;
+        __serialize_unimplemented_method!(serialize_struct(&str, usize) -> SerializeStruct);
+    };
+    (struct_variant) => {
+        type SerializeStructVariant = $crate::ser::Impossible<Self::Ok, Self::Error>;
+        __serialize_unimplemented_method!(serialize_struct_variant(&str, u32, &str, usize) -> SerializeStructVariant);
+    };
+}

vendor/serde/src/private/mod.rs

@@ -0,0 +1,48 @@
+#[cfg(not(no_serde_derive))]
+pub mod de;
+#[cfg(not(no_serde_derive))]
+pub mod ser;
+
+// FIXME: #[cfg(doctest)] once https://github.com/rust-lang/rust/issues/67295 is fixed.
+pub mod doc;
+
+pub use crate::lib::clone::Clone;
+pub use crate::lib::convert::{From, Into};
+pub use crate::lib::default::Default;
+pub use crate::lib::fmt::{self, Formatter};
+pub use crate::lib::marker::PhantomData;
+pub use crate::lib::option::Option::{self, None, Some};
+pub use crate::lib::ptr;
+pub use crate::lib::result::Result::{self, Err, Ok};
+
+pub use self::string::from_utf8_lossy;
+
+#[cfg(any(feature = "alloc", feature = "std"))]
+pub use crate::lib::{ToString, Vec};
+
+#[cfg(not(no_core_try_from))]
+pub use crate::lib::convert::TryFrom;
+
+mod string {
+    use crate::lib::*;
+
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    pub fn from_utf8_lossy(bytes: &[u8]) -> Cow<str> {
+        String::from_utf8_lossy(bytes)
+    }
+
+    // The generated code calls this like:
+    //
+    //     let value = &_serde::__private::from_utf8_lossy(bytes);
+    //     Err(_serde::de::Error::unknown_variant(value, VARIANTS))
+    //
+    // so it is okay for the return type to be different from the std case as long
+    // as the above works.
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
+    pub fn from_utf8_lossy(bytes: &[u8]) -> &str {
+        // Three unicode replacement characters if it fails. They look like a
+        // white-on-black question mark. The user will recognize it as invalid
+        // UTF-8.
+        str::from_utf8(bytes).unwrap_or("\u{fffd}\u{fffd}\u{fffd}")
+    }
+}

vendor/serde/src/ser/fmt.rs

@@ -0,0 +1,170 @@
+use crate::lib::*;
+use crate::ser::{Error, Impossible, Serialize, Serializer};
+
+impl Error for fmt::Error {
+    fn custom<T: Display>(_msg: T) -> Self {
+        fmt::Error
+    }
+}
+
+macro_rules! fmt_primitives {
+    ($($f:ident: $t:ty,)*) => {
+        $(
+            fn $f(self, v: $t) -> fmt::Result {
+                Display::fmt(&v, self)
+            }
+        )*
+    };
+}
+
+/// ```edition2021
+/// use serde::ser::Serialize;
+/// use serde_derive::Serialize;
+/// use std::fmt::{self, Display};
+///
+/// #[derive(Serialize)]
+/// #[serde(rename_all = "kebab-case")]
+/// pub enum MessageType {
+///     StartRequest,
+///     EndRequest,
+/// }
+///
+/// impl Display for MessageType {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         self.serialize(f)
+///     }
+/// }
+/// ```
+impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
+    type Ok = ();
+    type Error = fmt::Error;
+    type SerializeSeq = Impossible<(), fmt::Error>;
+    type SerializeTuple = Impossible<(), fmt::Error>;
+    type SerializeTupleStruct = Impossible<(), fmt::Error>;
+    type SerializeTupleVariant = Impossible<(), fmt::Error>;
+    type SerializeMap = Impossible<(), fmt::Error>;
+    type SerializeStruct = Impossible<(), fmt::Error>;
+    type SerializeStructVariant = Impossible<(), fmt::Error>;
+
+    fmt_primitives! {
+        serialize_bool: bool,
+        serialize_i8: i8,
+        serialize_i16: i16,
+        serialize_i32: i32,
+        serialize_i64: i64,
+        serialize_i128: i128,
+        serialize_u8: u8,
+        serialize_u16: u16,
+        serialize_u32: u32,
+        serialize_u64: u64,
+        serialize_u128: u128,
+        serialize_f32: f32,
+        serialize_f64: f64,
+        serialize_char: char,
+        serialize_str: &str,
+        serialize_unit_struct: &'static str,
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        variant: &'static str,
+    ) -> fmt::Result {
+        Display::fmt(variant, self)
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Serialize::serialize(value, self)
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_none(self) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Err(fmt::Error)
+    }
+
+    fn serialize_unit(self) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T,
+    ) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Err(fmt::Error)
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleStruct, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStruct, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn collect_str<T: ?Sized>(self, value: &T) -> fmt::Result
+    where
+        T: Display,
+    {
+        Display::fmt(value, self)
+    }
+}

vendor/serde/src/ser/impossible.rs

@@ -0,0 +1,216 @@
+//! This module contains `Impossible` serializer and its implementations.
+
+use crate::lib::*;
+
+use crate::ser::{
+    self, Serialize, SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant,
+    SerializeTuple, SerializeTupleStruct, SerializeTupleVariant,
+};
+
+/// Helper type for implementing a `Serializer` that does not support
+/// serializing one of the compound types.
+///
+/// This type cannot be instantiated, but implements every one of the traits
+/// corresponding to the [`Serializer`] compound types: [`SerializeSeq`],
+/// [`SerializeTuple`], [`SerializeTupleStruct`], [`SerializeTupleVariant`],
+/// [`SerializeMap`], [`SerializeStruct`], and [`SerializeStructVariant`].
+///
+/// ```edition2021
+/// # use serde::ser::{Serializer, Impossible};
+/// # use serde::__private::doc::Error;
+/// #
+/// # struct MySerializer;
+/// #
+/// impl Serializer for MySerializer {
+///     type Ok = ();
+///     type Error = Error;
+///
+///     type SerializeSeq = Impossible<(), Error>;
+///     /* other associated types */
+///
+///     /// This data format does not support serializing sequences.
+///     fn serialize_seq(self,
+///                      len: Option<usize>)
+///                      -> Result<Self::SerializeSeq, Error> {
+///         // Given Impossible cannot be instantiated, the only
+///         // thing we can do here is to return an error.
+/// #         stringify! {
+///         Err(...)
+/// #         };
+/// #         unimplemented!()
+///     }
+///
+///     /* other Serializer methods */
+/// #     serde::__serialize_unimplemented! {
+/// #         bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str bytes none some
+/// #         unit unit_struct unit_variant newtype_struct newtype_variant
+/// #         tuple tuple_struct tuple_variant map struct struct_variant
+/// #     }
+/// }
+/// ```
+///
+/// [`Serializer`]: trait.Serializer.html
+/// [`SerializeSeq`]: trait.SerializeSeq.html
+/// [`SerializeTuple`]: trait.SerializeTuple.html
+/// [`SerializeTupleStruct`]: trait.SerializeTupleStruct.html
+/// [`SerializeTupleVariant`]: trait.SerializeTupleVariant.html
+/// [`SerializeMap`]: trait.SerializeMap.html
+/// [`SerializeStruct`]: trait.SerializeStruct.html
+/// [`SerializeStructVariant`]: trait.SerializeStructVariant.html
+pub struct Impossible<Ok, Error> {
+    void: Void,
+    ok: PhantomData<Ok>,
+    error: PhantomData<Error>,
+}
+
+enum Void {}
+
+impl<Ok, Error> SerializeSeq for Impossible<Ok, Error>
+where
+    Error: ser::Error,
+{
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = value;
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        match self.void {}
+    }
+}
+
+impl<Ok, Error> SerializeTuple for Impossible<Ok, Error>
+where
+    Error: ser::Error,
+{
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = value;
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        match self.void {}
+    }
+}
+
+impl<Ok, Error> SerializeTupleStruct for Impossible<Ok, Error>
+where
+    Error: ser::Error,
+{
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = value;
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        match self.void {}
+    }
+}
+
+impl<Ok, Error> SerializeTupleVariant for Impossible<Ok, Error>
+where
+    Error: ser::Error,
+{
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = value;
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        match self.void {}
+    }
+}
+
+impl<Ok, Error> SerializeMap for Impossible<Ok, Error>
+where
+    Error: ser::Error,
+{
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = key;
+        match self.void {}
+    }
+
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = value;
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        match self.void {}
+    }
+}
+
+impl<Ok, Error> SerializeStruct for Impossible<Ok, Error>
+where
+    Error: ser::Error,
+{
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = key;
+        let _ = value;
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        match self.void {}
+    }
+}
+
+impl<Ok, Error> SerializeStructVariant for Impossible<Ok, Error>
+where
+    Error: ser::Error,
+{
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error>
+    where
+        T: Serialize,
+    {
+        let _ = key;
+        let _ = value;
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        match self.void {}
+    }
+}

vendor/serde/src/std_error.rs

@@ -0,0 +1,48 @@
+use crate::lib::{Debug, Display};
+
+/// Either a re-export of std::error::Error or a new identical trait, depending
+/// on whether Serde's "std" feature is enabled.
+///
+/// Serde's error traits [`serde::ser::Error`] and [`serde::de::Error`] require
+/// [`std::error::Error`] as a supertrait, but only when Serde is built with
+/// "std" enabled. Data formats that don't care about no\_std support should
+/// generally provide their error types with a `std::error::Error` impl
+/// directly:
+///
+/// ```edition2021
+/// #[derive(Debug)]
+/// struct MySerError {...}
+///
+/// impl serde::ser::Error for MySerError {...}
+///
+/// impl std::fmt::Display for MySerError {...}
+///
+/// // We don't support no_std!
+/// impl std::error::Error for MySerError {}
+/// ```
+///
+/// Data formats that *do* support no\_std may either have a "std" feature of
+/// their own:
+///
+/// ```toml
+/// [features]
+/// std = ["serde/std"]
+/// ```
+///
+/// ```edition2021
+/// #[cfg(feature = "std")]
+/// impl std::error::Error for MySerError {}
+/// ```
+///
+/// ... or else provide the std Error impl unconditionally via Serde's
+/// re-export:
+///
+/// ```edition2021
+/// impl serde::ser::StdError for MySerError {}
+/// ```
+pub trait Error: Debug + Display {
+    /// The underlying cause of this error, if any.
+    fn source(&self) -> Option<&(Error + 'static)> {
+        None
+    }
+}