Initial vendor packages

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

1 files changed, 2679 insertions, 0 deletions

diff --git a/vendor/serde_json/src/de.rs b/vendor/serde_json/src/de.rs
new file mode 100644
index 0000000..7154f84
--- /dev/null
+++ b/vendor/serde_json/src/de.rs
@@ -0,0 +1,2679 @@
+//! Deserialize JSON data to a Rust data structure.
+
+use crate::error::{Error, ErrorCode, Result};
+#[cfg(feature = "float_roundtrip")]
+use crate::lexical;
+use crate::number::Number;
+use crate::read::{self, Fused, Reference};
+use alloc::string::String;
+use alloc::vec::Vec;
+#[cfg(feature = "float_roundtrip")]
+use core::iter;
+use core::iter::FusedIterator;
+use core::marker::PhantomData;
+use core::result;
+use core::str::FromStr;
+use serde::de::{self, Expected, Unexpected};
+use serde::forward_to_deserialize_any;
+
+#[cfg(feature = "arbitrary_precision")]
+use crate::number::NumberDeserializer;
+
+pub use crate::read::{Read, SliceRead, StrRead};
+
+#[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+pub use crate::read::IoRead;
+
+//////////////////////////////////////////////////////////////////////////////
+
+/// A structure that deserializes JSON into Rust values.
+pub struct Deserializer<R> {
+    read: R,
+    scratch: Vec<u8>,
+    remaining_depth: u8,
+    #[cfg(feature = "float_roundtrip")]
+    single_precision: bool,
+    #[cfg(feature = "unbounded_depth")]
+    disable_recursion_limit: bool,
+}
+
+impl<'de, R> Deserializer<R>
+where
+    R: read::Read<'de>,
+{
+    /// Create a JSON deserializer from one of the possible serde_json input
+    /// sources.
+    ///
+    /// Typically it is more convenient to use one of these methods instead:
+    ///
+    ///   - Deserializer::from_str
+    ///   - Deserializer::from_slice
+    ///   - Deserializer::from_reader
+    pub fn new(read: R) -> Self {
+        Deserializer {
+            read,
+            scratch: Vec::new(),
+            remaining_depth: 128,
+            #[cfg(feature = "float_roundtrip")]
+            single_precision: false,
+            #[cfg(feature = "unbounded_depth")]
+            disable_recursion_limit: false,
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl<R> Deserializer<read::IoRead<R>>
+where
+    R: crate::io::Read,
+{
+    /// Creates a JSON deserializer from an `io::Read`.
+    ///
+    /// Reader-based deserializers do not support deserializing borrowed types
+    /// like `&str`, since the `std::io::Read` trait has no non-copying methods
+    /// -- everything it does involves copying bytes out of the data source.
+    pub fn from_reader(reader: R) -> Self {
+        Deserializer::new(read::IoRead::new(reader))
+    }
+}
+
+impl<'a> Deserializer<read::SliceRead<'a>> {
+    /// Creates a JSON deserializer from a `&[u8]`.
+    pub fn from_slice(bytes: &'a [u8]) -> Self {
+        Deserializer::new(read::SliceRead::new(bytes))
+    }
+}
+
+impl<'a> Deserializer<read::StrRead<'a>> {
+    /// Creates a JSON deserializer from a `&str`.
+    pub fn from_str(s: &'a str) -> Self {
+        Deserializer::new(read::StrRead::new(s))
+    }
+}
+
+macro_rules! overflow {
+    ($a:ident * 10 + $b:ident, $c:expr) => {
+        match $c {
+            c => $a >= c / 10 && ($a > c / 10 || $b > c % 10),
+        }
+    };
+}
+
+pub(crate) enum ParserNumber {
+    F64(f64),
+    U64(u64),
+    I64(i64),
+    #[cfg(feature = "arbitrary_precision")]
+    String(String),
+}
+
+impl ParserNumber {
+    fn visit<'de, V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        match self {
+            ParserNumber::F64(x) => visitor.visit_f64(x),
+            ParserNumber::U64(x) => visitor.visit_u64(x),
+            ParserNumber::I64(x) => visitor.visit_i64(x),
+            #[cfg(feature = "arbitrary_precision")]
+            ParserNumber::String(x) => visitor.visit_map(NumberDeserializer { number: x.into() }),
+        }
+    }
+
+    fn invalid_type(self, exp: &dyn Expected) -> Error {
+        match self {
+            ParserNumber::F64(x) => de::Error::invalid_type(Unexpected::Float(x), exp),
+            ParserNumber::U64(x) => de::Error::invalid_type(Unexpected::Unsigned(x), exp),
+            ParserNumber::I64(x) => de::Error::invalid_type(Unexpected::Signed(x), exp),
+            #[cfg(feature = "arbitrary_precision")]
+            ParserNumber::String(_) => de::Error::invalid_type(Unexpected::Other("number"), exp),
+        }
+    }
+}
+
+impl<'de, R: Read<'de>> Deserializer<R> {
+    /// The `Deserializer::end` method should be called after a value has been fully deserialized.
+    /// This allows the `Deserializer` to validate that the input stream is at the end or that it
+    /// only has trailing whitespace.
+    pub fn end(&mut self) -> Result<()> {
+        match tri!(self.parse_whitespace()) {
+            Some(_) => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+            None => Ok(()),
+        }
+    }
+
+    /// Turn a JSON deserializer into an iterator over values of type T.
+    pub fn into_iter<T>(self) -> StreamDeserializer<'de, R, T>
+    where
+        T: de::Deserialize<'de>,
+    {
+        // This cannot be an implementation of std::iter::IntoIterator because
+        // we need the caller to choose what T is.
+        let offset = self.read.byte_offset();
+        StreamDeserializer {
+            de: self,
+            offset,
+            failed: false,
+            output: PhantomData,
+            lifetime: PhantomData,
+        }
+    }
+
+    /// Parse arbitrarily deep JSON structures without any consideration for
+    /// overflowing the stack.
+    ///
+    /// You will want to provide some other way to protect against stack
+    /// overflows, such as by wrapping your Deserializer in the dynamically
+    /// growing stack adapter provided by the serde_stacker crate. Additionally
+    /// you will need to be careful around other recursive operations on the
+    /// parsed result which may overflow the stack after deserialization has
+    /// completed, including, but not limited to, Display and Debug and Drop
+    /// impls.
+    ///
+    /// *This method is only available if serde_json is built with the
+    /// `"unbounded_depth"` feature.*
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use serde::Deserialize;
+    /// use serde_json::Value;
+    ///
+    /// fn main() {
+    ///     let mut json = String::new();
+    ///     for _ in 0..10000 {
+    ///         json = format!("[{}]", json);
+    ///     }
+    ///
+    ///     let mut deserializer = serde_json::Deserializer::from_str(&json);
+    ///     deserializer.disable_recursion_limit();
+    ///     let deserializer = serde_stacker::Deserializer::new(&mut deserializer);
+    ///     let value = Value::deserialize(deserializer).unwrap();
+    ///
+    ///     carefully_drop_nested_arrays(value);
+    /// }
+    ///
+    /// fn carefully_drop_nested_arrays(value: Value) {
+    ///     let mut stack = vec![value];
+    ///     while let Some(value) = stack.pop() {
+    ///         if let Value::Array(array) = value {
+    ///             stack.extend(array);
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    #[cfg(feature = "unbounded_depth")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "unbounded_depth")))]
+    pub fn disable_recursion_limit(&mut self) {
+        self.disable_recursion_limit = true;
+    }
+
+    pub(crate) fn peek(&mut self) -> Result<Option<u8>> {
+        self.read.peek()
+    }
+
+    fn peek_or_null(&mut self) -> Result<u8> {
+        Ok(tri!(self.peek()).unwrap_or(b'\x00'))
+    }
+
+    fn eat_char(&mut self) {
+        self.read.discard();
+    }
+
+    fn next_char(&mut self) -> Result<Option<u8>> {
+        self.read.next()
+    }
+
+    fn next_char_or_null(&mut self) -> Result<u8> {
+        Ok(tri!(self.next_char()).unwrap_or(b'\x00'))
+    }
+
+    /// Error caused by a byte from next_char().
+    #[cold]
+    fn error(&self, reason: ErrorCode) -> Error {
+        let position = self.read.position();
+        Error::syntax(reason, position.line, position.column)
+    }
+
+    /// Error caused by a byte from peek().
+    #[cold]
+    fn peek_error(&self, reason: ErrorCode) -> Error {
+        let position = self.read.peek_position();
+        Error::syntax(reason, position.line, position.column)
+    }
+
+    /// Returns the first non-whitespace byte without consuming it, or `None` if
+    /// EOF is encountered.
+    fn parse_whitespace(&mut self) -> Result<Option<u8>> {
+        loop {
+            match tri!(self.peek()) {
+                Some(b' ' | b'\n' | b'\t' | b'\r') => {
+                    self.eat_char();
+                }
+                other => {
+                    return Ok(other);
+                }
+            }
+        }
+    }
+
+    #[cold]
+    fn peek_invalid_type(&mut self, exp: &dyn Expected) -> Error {
+        let err = match self.peek_or_null().unwrap_or(b'\x00') {
+            b'n' => {
+                self.eat_char();
+                if let Err(err) = self.parse_ident(b"ull") {
+                    return err;
+                }
+                de::Error::invalid_type(Unexpected::Unit, exp)
+            }
+            b't' => {
+                self.eat_char();
+                if let Err(err) = self.parse_ident(b"rue") {
+                    return err;
+                }
+                de::Error::invalid_type(Unexpected::Bool(true), exp)
+            }
+            b'f' => {
+                self.eat_char();
+                if let Err(err) = self.parse_ident(b"alse") {
+                    return err;
+                }
+                de::Error::invalid_type(Unexpected::Bool(false), exp)
+            }
+            b'-' => {
+                self.eat_char();
+                match self.parse_any_number(false) {
+                    Ok(n) => n.invalid_type(exp),
+                    Err(err) => return err,
+                }
+            }
+            b'0'..=b'9' => match self.parse_any_number(true) {
+                Ok(n) => n.invalid_type(exp),
+                Err(err) => return err,
+            },
+            b'"' => {
+                self.eat_char();
+                self.scratch.clear();
+                match self.read.parse_str(&mut self.scratch) {
+                    Ok(s) => de::Error::invalid_type(Unexpected::Str(&s), exp),
+                    Err(err) => return err,
+                }
+            }
+            b'[' => de::Error::invalid_type(Unexpected::Seq, exp),
+            b'{' => de::Error::invalid_type(Unexpected::Map, exp),
+            _ => self.peek_error(ErrorCode::ExpectedSomeValue),
+        };
+
+        self.fix_position(err)
+    }
+
+    pub(crate) fn deserialize_number<'any, V>(&mut self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'any>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'-' => {
+                self.eat_char();
+                tri!(self.parse_integer(false)).visit(visitor)
+            }
+            b'0'..=b'9' => tri!(self.parse_integer(true)).visit(visitor),
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    #[cfg(feature = "float_roundtrip")]
+    pub(crate) fn do_deserialize_f32<'any, V>(&mut self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'any>,
+    {
+        self.single_precision = true;
+        let val = self.deserialize_number(visitor);
+        self.single_precision = false;
+        val
+    }
+
+    pub(crate) fn do_deserialize_i128<'any, V>(&mut self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'any>,
+    {
+        let mut buf = String::new();
+
+        match tri!(self.parse_whitespace()) {
+            Some(b'-') => {
+                self.eat_char();
+                buf.push('-');
+            }
+            Some(_) => {}
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        tri!(self.scan_integer128(&mut buf));
+
+        let value = match buf.parse() {
+            Ok(int) => visitor.visit_i128(int),
+            Err(_) => {
+                return Err(self.error(ErrorCode::NumberOutOfRange));
+            }
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    pub(crate) fn do_deserialize_u128<'any, V>(&mut self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'any>,
+    {
+        match tri!(self.parse_whitespace()) {
+            Some(b'-') => {
+                return Err(self.peek_error(ErrorCode::NumberOutOfRange));
+            }
+            Some(_) => {}
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        }
+
+        let mut buf = String::new();
+        tri!(self.scan_integer128(&mut buf));
+
+        let value = match buf.parse() {
+            Ok(int) => visitor.visit_u128(int),
+            Err(_) => {
+                return Err(self.error(ErrorCode::NumberOutOfRange));
+            }
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    fn scan_integer128(&mut self, buf: &mut String) -> Result<()> {
+        match tri!(self.next_char_or_null()) {
+            b'0' => {
+                buf.push('0');
+                // There can be only one leading '0'.
+                match tri!(self.peek_or_null()) {
+                    b'0'..=b'9' => Err(self.peek_error(ErrorCode::InvalidNumber)),
+                    _ => Ok(()),
+                }
+            }
+            c @ b'1'..=b'9' => {
+                buf.push(c as char);
+                while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+                    self.eat_char();
+                    buf.push(c as char);
+                }
+                Ok(())
+            }
+            _ => Err(self.error(ErrorCode::InvalidNumber)),
+        }
+    }
+
+    #[cold]
+    fn fix_position(&self, err: Error) -> Error {
+        err.fix_position(move |code| self.error(code))
+    }
+
+    fn parse_ident(&mut self, ident: &[u8]) -> Result<()> {
+        for expected in ident {
+            match tri!(self.next_char()) {
+                None => {
+                    return Err(self.error(ErrorCode::EofWhileParsingValue));
+                }
+                Some(next) => {
+                    if next != *expected {
+                        return Err(self.error(ErrorCode::ExpectedSomeIdent));
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn parse_integer(&mut self, positive: bool) -> Result<ParserNumber> {
+        let next = match tri!(self.next_char()) {
+            Some(b) => b,
+            None => {
+                return Err(self.error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        match next {
+            b'0' => {
+                // There can be only one leading '0'.
+                match tri!(self.peek_or_null()) {
+                    b'0'..=b'9' => Err(self.peek_error(ErrorCode::InvalidNumber)),
+                    _ => self.parse_number(positive, 0),
+                }
+            }
+            c @ b'1'..=b'9' => {
+                let mut significand = (c - b'0') as u64;
+
+                loop {
+                    match tri!(self.peek_or_null()) {
+                        c @ b'0'..=b'9' => {
+                            let digit = (c - b'0') as u64;
+
+                            // We need to be careful with overflow. If we can,
+                            // try to keep the number as a `u64` until we grow
+                            // too large. At that point, switch to parsing the
+                            // value as a `f64`.
+                            if overflow!(significand * 10 + digit, u64::max_value()) {
+                                return Ok(ParserNumber::F64(tri!(
+                                    self.parse_long_integer(positive, significand),
+                                )));
+                            }
+
+                            self.eat_char();
+                            significand = significand * 10 + digit;
+                        }
+                        _ => {
+                            return self.parse_number(positive, significand);
+                        }
+                    }
+                }
+            }
+            _ => Err(self.error(ErrorCode::InvalidNumber)),
+        }
+    }
+
+    fn parse_number(&mut self, positive: bool, significand: u64) -> Result<ParserNumber> {
+        Ok(match tri!(self.peek_or_null()) {
+            b'.' => ParserNumber::F64(tri!(self.parse_decimal(positive, significand, 0))),
+            b'e' | b'E' => ParserNumber::F64(tri!(self.parse_exponent(positive, significand, 0))),
+            _ => {
+                if positive {
+                    ParserNumber::U64(significand)
+                } else {
+                    let neg = (significand as i64).wrapping_neg();
+
+                    // Convert into a float if we underflow, or on `-0`.
+                    if neg >= 0 {
+                        ParserNumber::F64(-(significand as f64))
+                    } else {
+                        ParserNumber::I64(neg)
+                    }
+                }
+            }
+        })
+    }
+
+    fn parse_decimal(
+        &mut self,
+        positive: bool,
+        mut significand: u64,
+        exponent_before_decimal_point: i32,
+    ) -> Result<f64> {
+        self.eat_char();
+
+        let mut exponent_after_decimal_point = 0;
+        while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+            let digit = (c - b'0') as u64;
+
+            if overflow!(significand * 10 + digit, u64::max_value()) {
+                let exponent = exponent_before_decimal_point + exponent_after_decimal_point;
+                return self.parse_decimal_overflow(positive, significand, exponent);
+            }
+
+            self.eat_char();
+            significand = significand * 10 + digit;
+            exponent_after_decimal_point -= 1;
+        }
+
+        // Error if there is not at least one digit after the decimal point.
+        if exponent_after_decimal_point == 0 {
+            match tri!(self.peek()) {
+                Some(_) => return Err(self.peek_error(ErrorCode::InvalidNumber)),
+                None => return Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+            }
+        }
+
+        let exponent = exponent_before_decimal_point + exponent_after_decimal_point;
+        match tri!(self.peek_or_null()) {
+            b'e' | b'E' => self.parse_exponent(positive, significand, exponent),
+            _ => self.f64_from_parts(positive, significand, exponent),
+        }
+    }
+
+    fn parse_exponent(
+        &mut self,
+        positive: bool,
+        significand: u64,
+        starting_exp: i32,
+    ) -> Result<f64> {
+        self.eat_char();
+
+        let positive_exp = match tri!(self.peek_or_null()) {
+            b'+' => {
+                self.eat_char();
+                true
+            }
+            b'-' => {
+                self.eat_char();
+                false
+            }
+            _ => true,
+        };
+
+        let next = match tri!(self.next_char()) {
+            Some(b) => b,
+            None => {
+                return Err(self.error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        // Make sure a digit follows the exponent place.
+        let mut exp = match next {
+            c @ b'0'..=b'9' => (c - b'0') as i32,
+            _ => {
+                return Err(self.error(ErrorCode::InvalidNumber));
+            }
+        };
+
+        while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+            let digit = (c - b'0') as i32;
+
+            if overflow!(exp * 10 + digit, i32::max_value()) {
+                let zero_significand = significand == 0;
+                return self.parse_exponent_overflow(positive, zero_significand, positive_exp);
+            }
+
+            exp = exp * 10 + digit;
+        }
+
+        let final_exp = if positive_exp {
+            starting_exp.saturating_add(exp)
+        } else {
+            starting_exp.saturating_sub(exp)
+        };
+
+        self.f64_from_parts(positive, significand, final_exp)
+    }
+
+    #[cfg(feature = "float_roundtrip")]
+    fn f64_from_parts(&mut self, positive: bool, significand: u64, exponent: i32) -> Result<f64> {
+        let f = if self.single_precision {
+            lexical::parse_concise_float::<f32>(significand, exponent) as f64
+        } else {
+            lexical::parse_concise_float::<f64>(significand, exponent)
+        };
+
+        if f.is_infinite() {
+            Err(self.error(ErrorCode::NumberOutOfRange))
+        } else {
+            Ok(if positive { f } else { -f })
+        }
+    }
+
+    #[cfg(not(feature = "float_roundtrip"))]
+    fn f64_from_parts(
+        &mut self,
+        positive: bool,
+        significand: u64,
+        mut exponent: i32,
+    ) -> Result<f64> {
+        let mut f = significand as f64;
+        loop {
+            match POW10.get(exponent.wrapping_abs() as usize) {
+                Some(&pow) => {
+                    if exponent >= 0 {
+                        f *= pow;
+                        if f.is_infinite() {
+                            return Err(self.error(ErrorCode::NumberOutOfRange));
+                        }
+                    } else {
+                        f /= pow;
+                    }
+                    break;
+                }
+                None => {
+                    if f == 0.0 {
+                        break;
+                    }
+                    if exponent >= 0 {
+                        return Err(self.error(ErrorCode::NumberOutOfRange));
+                    }
+                    f /= 1e308;
+                    exponent += 308;
+                }
+            }
+        }
+        Ok(if positive { f } else { -f })
+    }
+
+    #[cfg(feature = "float_roundtrip")]
+    #[cold]
+    #[inline(never)]
+    fn parse_long_integer(&mut self, positive: bool, partial_significand: u64) -> Result<f64> {
+        // To deserialize floats we'll first push the integer and fraction
+        // parts, both as byte strings, into the scratch buffer and then feed
+        // both slices to lexical's parser. For example if the input is
+        // `12.34e5` we'll push b"1234" into scratch and then pass b"12" and
+        // b"34" to lexical. `integer_end` will be used to track where to split
+        // the scratch buffer.
+        //
+        // Note that lexical expects the integer part to contain *no* leading
+        // zeroes and the fraction part to contain *no* trailing zeroes. The
+        // first requirement is already handled by the integer parsing logic.
+        // The second requirement will be enforced just before passing the
+        // slices to lexical in f64_long_from_parts.
+        self.scratch.clear();
+        self.scratch
+            .extend_from_slice(itoa::Buffer::new().format(partial_significand).as_bytes());
+
+        loop {
+            match tri!(self.peek_or_null()) {
+                c @ b'0'..=b'9' => {
+                    self.scratch.push(c);
+                    self.eat_char();
+                }
+                b'.' => {
+                    self.eat_char();
+                    return self.parse_long_decimal(positive, self.scratch.len());
+                }
+                b'e' | b'E' => {
+                    return self.parse_long_exponent(positive, self.scratch.len());
+                }
+                _ => {
+                    return self.f64_long_from_parts(positive, self.scratch.len(), 0);
+                }
+            }
+        }
+    }
+
+    #[cfg(not(feature = "float_roundtrip"))]
+    #[cold]
+    #[inline(never)]
+    fn parse_long_integer(&mut self, positive: bool, significand: u64) -> Result<f64> {
+        let mut exponent = 0;
+        loop {
+            match tri!(self.peek_or_null()) {
+                b'0'..=b'9' => {
+                    self.eat_char();
+                    // This could overflow... if your integer is gigabytes long.
+                    // Ignore that possibility.
+                    exponent += 1;
+                }
+                b'.' => {
+                    return self.parse_decimal(positive, significand, exponent);
+                }
+                b'e' | b'E' => {
+                    return self.parse_exponent(positive, significand, exponent);
+                }
+                _ => {
+                    return self.f64_from_parts(positive, significand, exponent);
+                }
+            }
+        }
+    }
+
+    #[cfg(feature = "float_roundtrip")]
+    #[cold]
+    fn parse_long_decimal(&mut self, positive: bool, integer_end: usize) -> Result<f64> {
+        let mut at_least_one_digit = integer_end < self.scratch.len();
+        while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.scratch.push(c);
+            self.eat_char();
+            at_least_one_digit = true;
+        }
+
+        if !at_least_one_digit {
+            match tri!(self.peek()) {
+                Some(_) => return Err(self.peek_error(ErrorCode::InvalidNumber)),
+                None => return Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+            }
+        }
+
+        match tri!(self.peek_or_null()) {
+            b'e' | b'E' => self.parse_long_exponent(positive, integer_end),
+            _ => self.f64_long_from_parts(positive, integer_end, 0),
+        }
+    }
+
+    #[cfg(feature = "float_roundtrip")]
+    fn parse_long_exponent(&mut self, positive: bool, integer_end: usize) -> Result<f64> {
+        self.eat_char();
+
+        let positive_exp = match tri!(self.peek_or_null()) {
+            b'+' => {
+                self.eat_char();
+                true
+            }
+            b'-' => {
+                self.eat_char();
+                false
+            }
+            _ => true,
+        };
+
+        let next = match tri!(self.next_char()) {
+            Some(b) => b,
+            None => {
+                return Err(self.error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        // Make sure a digit follows the exponent place.
+        let mut exp = match next {
+            c @ b'0'..=b'9' => (c - b'0') as i32,
+            _ => {
+                return Err(self.error(ErrorCode::InvalidNumber));
+            }
+        };
+
+        while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+            let digit = (c - b'0') as i32;
+
+            if overflow!(exp * 10 + digit, i32::max_value()) {
+                let zero_significand = self.scratch.iter().all(|&digit| digit == b'0');
+                return self.parse_exponent_overflow(positive, zero_significand, positive_exp);
+            }
+
+            exp = exp * 10 + digit;
+        }
+
+        let final_exp = if positive_exp { exp } else { -exp };
+
+        self.f64_long_from_parts(positive, integer_end, final_exp)
+    }
+
+    // This cold code should not be inlined into the middle of the hot
+    // decimal-parsing loop above.
+    #[cfg(feature = "float_roundtrip")]
+    #[cold]
+    #[inline(never)]
+    fn parse_decimal_overflow(
+        &mut self,
+        positive: bool,
+        significand: u64,
+        exponent: i32,
+    ) -> Result<f64> {
+        let mut buffer = itoa::Buffer::new();
+        let significand = buffer.format(significand);
+        let fraction_digits = -exponent as usize;
+        self.scratch.clear();
+        if let Some(zeros) = fraction_digits.checked_sub(significand.len() + 1) {
+            self.scratch.extend(iter::repeat(b'0').take(zeros + 1));
+        }
+        self.scratch.extend_from_slice(significand.as_bytes());
+        let integer_end = self.scratch.len() - fraction_digits;
+        self.parse_long_decimal(positive, integer_end)
+    }
+
+    #[cfg(not(feature = "float_roundtrip"))]
+    #[cold]
+    #[inline(never)]
+    fn parse_decimal_overflow(
+        &mut self,
+        positive: bool,
+        significand: u64,
+        exponent: i32,
+    ) -> Result<f64> {
+        // The next multiply/add would overflow, so just ignore all further
+        // digits.
+        while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+        }
+
+        match tri!(self.peek_or_null()) {
+            b'e' | b'E' => self.parse_exponent(positive, significand, exponent),
+            _ => self.f64_from_parts(positive, significand, exponent),
+        }
+    }
+
+    // This cold code should not be inlined into the middle of the hot
+    // exponent-parsing loop above.
+    #[cold]
+    #[inline(never)]
+    fn parse_exponent_overflow(
+        &mut self,
+        positive: bool,
+        zero_significand: bool,
+        positive_exp: bool,
+    ) -> Result<f64> {
+        // Error instead of +/- infinity.
+        if !zero_significand && positive_exp {
+            return Err(self.error(ErrorCode::NumberOutOfRange));
+        }
+
+        while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+        }
+        Ok(if positive { 0.0 } else { -0.0 })
+    }
+
+    #[cfg(feature = "float_roundtrip")]
+    fn f64_long_from_parts(
+        &mut self,
+        positive: bool,
+        integer_end: usize,
+        exponent: i32,
+    ) -> Result<f64> {
+        let integer = &self.scratch[..integer_end];
+        let fraction = &self.scratch[integer_end..];
+
+        let f = if self.single_precision {
+            lexical::parse_truncated_float::<f32>(integer, fraction, exponent) as f64
+        } else {
+            lexical::parse_truncated_float::<f64>(integer, fraction, exponent)
+        };
+
+        if f.is_infinite() {
+            Err(self.error(ErrorCode::NumberOutOfRange))
+        } else {
+            Ok(if positive { f } else { -f })
+        }
+    }
+
+    fn parse_any_signed_number(&mut self) -> Result<ParserNumber> {
+        let peek = match tri!(self.peek()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'-' => {
+                self.eat_char();
+                self.parse_any_number(false)
+            }
+            b'0'..=b'9' => self.parse_any_number(true),
+            _ => Err(self.peek_error(ErrorCode::InvalidNumber)),
+        };
+
+        let value = match tri!(self.peek()) {
+            Some(_) => Err(self.peek_error(ErrorCode::InvalidNumber)),
+            None => value,
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            // The de::Error impl creates errors with unknown line and column.
+            // Fill in the position here by looking at the current index in the
+            // input. There is no way to tell whether this should call `error`
+            // or `peek_error` so pick the one that seems correct more often.
+            // Worst case, the position is off by one character.
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    #[cfg(not(feature = "arbitrary_precision"))]
+    fn parse_any_number(&mut self, positive: bool) -> Result<ParserNumber> {
+        self.parse_integer(positive)
+    }
+
+    #[cfg(feature = "arbitrary_precision")]
+    fn parse_any_number(&mut self, positive: bool) -> Result<ParserNumber> {
+        let mut buf = String::with_capacity(16);
+        if !positive {
+            buf.push('-');
+        }
+        tri!(self.scan_integer(&mut buf));
+        if positive {
+            if let Ok(unsigned) = buf.parse() {
+                return Ok(ParserNumber::U64(unsigned));
+            }
+        } else {
+            if let Ok(signed) = buf.parse() {
+                return Ok(ParserNumber::I64(signed));
+            }
+        }
+        Ok(ParserNumber::String(buf))
+    }
+
+    #[cfg(feature = "arbitrary_precision")]
+    fn scan_or_eof(&mut self, buf: &mut String) -> Result<u8> {
+        match tri!(self.next_char()) {
+            Some(b) => {
+                buf.push(b as char);
+                Ok(b)
+            }
+            None => Err(self.error(ErrorCode::EofWhileParsingValue)),
+        }
+    }
+
+    #[cfg(feature = "arbitrary_precision")]
+    fn scan_integer(&mut self, buf: &mut String) -> Result<()> {
+        match tri!(self.scan_or_eof(buf)) {
+            b'0' => {
+                // There can be only one leading '0'.
+                match tri!(self.peek_or_null()) {
+                    b'0'..=b'9' => Err(self.peek_error(ErrorCode::InvalidNumber)),
+                    _ => self.scan_number(buf),
+                }
+            }
+            b'1'..=b'9' => loop {
+                match tri!(self.peek_or_null()) {
+                    c @ b'0'..=b'9' => {
+                        self.eat_char();
+                        buf.push(c as char);
+                    }
+                    _ => {
+                        return self.scan_number(buf);
+                    }
+                }
+            },
+            _ => Err(self.error(ErrorCode::InvalidNumber)),
+        }
+    }
+
+    #[cfg(feature = "arbitrary_precision")]
+    fn scan_number(&mut self, buf: &mut String) -> Result<()> {
+        match tri!(self.peek_or_null()) {
+            b'.' => self.scan_decimal(buf),
+            e @ (b'e' | b'E') => self.scan_exponent(e as char, buf),
+            _ => Ok(()),
+        }
+    }
+
+    #[cfg(feature = "arbitrary_precision")]
+    fn scan_decimal(&mut self, buf: &mut String) -> Result<()> {
+        self.eat_char();
+        buf.push('.');
+
+        let mut at_least_one_digit = false;
+        while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+            buf.push(c as char);
+            at_least_one_digit = true;
+        }
+
+        if !at_least_one_digit {
+            match tri!(self.peek()) {
+                Some(_) => return Err(self.peek_error(ErrorCode::InvalidNumber)),
+                None => return Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+            }
+        }
+
+        match tri!(self.peek_or_null()) {
+            e @ (b'e' | b'E') => self.scan_exponent(e as char, buf),
+            _ => Ok(()),
+        }
+    }
+
+    #[cfg(feature = "arbitrary_precision")]
+    fn scan_exponent(&mut self, e: char, buf: &mut String) -> Result<()> {
+        self.eat_char();
+        buf.push(e);
+
+        match tri!(self.peek_or_null()) {
+            b'+' => {
+                self.eat_char();
+                buf.push('+');
+            }
+            b'-' => {
+                self.eat_char();
+                buf.push('-');
+            }
+            _ => {}
+        }
+
+        // Make sure a digit follows the exponent place.
+        match tri!(self.scan_or_eof(buf)) {
+            b'0'..=b'9' => {}
+            _ => {
+                return Err(self.error(ErrorCode::InvalidNumber));
+            }
+        }
+
+        while let c @ b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+            buf.push(c as char);
+        }
+
+        Ok(())
+    }
+
+    fn parse_object_colon(&mut self) -> Result<()> {
+        match tri!(self.parse_whitespace()) {
+            Some(b':') => {
+                self.eat_char();
+                Ok(())
+            }
+            Some(_) => Err(self.peek_error(ErrorCode::ExpectedColon)),
+            None => Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+        }
+    }
+
+    fn end_seq(&mut self) -> Result<()> {
+        match tri!(self.parse_whitespace()) {
+            Some(b']') => {
+                self.eat_char();
+                Ok(())
+            }
+            Some(b',') => {
+                self.eat_char();
+                match self.parse_whitespace() {
+                    Ok(Some(b']')) => Err(self.peek_error(ErrorCode::TrailingComma)),
+                    _ => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+                }
+            }
+            Some(_) => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+            None => Err(self.peek_error(ErrorCode::EofWhileParsingList)),
+        }
+    }
+
+    fn end_map(&mut self) -> Result<()> {
+        match tri!(self.parse_whitespace()) {
+            Some(b'}') => {
+                self.eat_char();
+                Ok(())
+            }
+            Some(b',') => Err(self.peek_error(ErrorCode::TrailingComma)),
+            Some(_) => Err(self.peek_error(ErrorCode::TrailingCharacters)),
+            None => Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+        }
+    }
+
+    fn ignore_value(&mut self) -> Result<()> {
+        self.scratch.clear();
+        let mut enclosing = None;
+
+        loop {
+            let peek = match tri!(self.parse_whitespace()) {
+                Some(b) => b,
+                None => {
+                    return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+                }
+            };
+
+            let frame = match peek {
+                b'n' => {
+                    self.eat_char();
+                    tri!(self.parse_ident(b"ull"));
+                    None
+                }
+                b't' => {
+                    self.eat_char();
+                    tri!(self.parse_ident(b"rue"));
+                    None
+                }
+                b'f' => {
+                    self.eat_char();
+                    tri!(self.parse_ident(b"alse"));
+                    None
+                }
+                b'-' => {
+                    self.eat_char();
+                    tri!(self.ignore_integer());
+                    None
+                }
+                b'0'..=b'9' => {
+                    tri!(self.ignore_integer());
+                    None
+                }
+                b'"' => {
+                    self.eat_char();
+                    tri!(self.read.ignore_str());
+                    None
+                }
+                frame @ (b'[' | b'{') => {
+                    self.scratch.extend(enclosing.take());
+                    self.eat_char();
+                    Some(frame)
+                }
+                _ => return Err(self.peek_error(ErrorCode::ExpectedSomeValue)),
+            };
+
+            let (mut accept_comma, mut frame) = match frame {
+                Some(frame) => (false, frame),
+                None => match enclosing.take() {
+                    Some(frame) => (true, frame),
+                    None => match self.scratch.pop() {
+                        Some(frame) => (true, frame),
+                        None => return Ok(()),
+                    },
+                },
+            };
+
+            loop {
+                match tri!(self.parse_whitespace()) {
+                    Some(b',') if accept_comma => {
+                        self.eat_char();
+                        break;
+                    }
+                    Some(b']') if frame == b'[' => {}
+                    Some(b'}') if frame == b'{' => {}
+                    Some(_) => {
+                        if accept_comma {
+                            return Err(self.peek_error(match frame {
+                                b'[' => ErrorCode::ExpectedListCommaOrEnd,
+                                b'{' => ErrorCode::ExpectedObjectCommaOrEnd,
+                                _ => unreachable!(),
+                            }));
+                        } else {
+                            break;
+                        }
+                    }
+                    None => {
+                        return Err(self.peek_error(match frame {
+                            b'[' => ErrorCode::EofWhileParsingList,
+                            b'{' => ErrorCode::EofWhileParsingObject,
+                            _ => unreachable!(),
+                        }));
+                    }
+                }
+
+                self.eat_char();
+                frame = match self.scratch.pop() {
+                    Some(frame) => frame,
+                    None => return Ok(()),
+                };
+                accept_comma = true;
+            }
+
+            if frame == b'{' {
+                match tri!(self.parse_whitespace()) {
+                    Some(b'"') => self.eat_char(),
+                    Some(_) => return Err(self.peek_error(ErrorCode::KeyMustBeAString)),
+                    None => return Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+                }
+                tri!(self.read.ignore_str());
+                match tri!(self.parse_whitespace()) {
+                    Some(b':') => self.eat_char(),
+                    Some(_) => return Err(self.peek_error(ErrorCode::ExpectedColon)),
+                    None => return Err(self.peek_error(ErrorCode::EofWhileParsingObject)),
+                }
+            }
+
+            enclosing = Some(frame);
+        }
+    }
+
+    fn ignore_integer(&mut self) -> Result<()> {
+        match tri!(self.next_char_or_null()) {
+            b'0' => {
+                // There can be only one leading '0'.
+                if let b'0'..=b'9' = tri!(self.peek_or_null()) {
+                    return Err(self.peek_error(ErrorCode::InvalidNumber));
+                }
+            }
+            b'1'..=b'9' => {
+                while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+                    self.eat_char();
+                }
+            }
+            _ => {
+                return Err(self.error(ErrorCode::InvalidNumber));
+            }
+        }
+
+        match tri!(self.peek_or_null()) {
+            b'.' => self.ignore_decimal(),
+            b'e' | b'E' => self.ignore_exponent(),
+            _ => Ok(()),
+        }
+    }
+
+    fn ignore_decimal(&mut self) -> Result<()> {
+        self.eat_char();
+
+        let mut at_least_one_digit = false;
+        while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+            at_least_one_digit = true;
+        }
+
+        if !at_least_one_digit {
+            return Err(self.peek_error(ErrorCode::InvalidNumber));
+        }
+
+        match tri!(self.peek_or_null()) {
+            b'e' | b'E' => self.ignore_exponent(),
+            _ => Ok(()),
+        }
+    }
+
+    fn ignore_exponent(&mut self) -> Result<()> {
+        self.eat_char();
+
+        match tri!(self.peek_or_null()) {
+            b'+' | b'-' => self.eat_char(),
+            _ => {}
+        }
+
+        // Make sure a digit follows the exponent place.
+        match tri!(self.next_char_or_null()) {
+            b'0'..=b'9' => {}
+            _ => {
+                return Err(self.error(ErrorCode::InvalidNumber));
+            }
+        }
+
+        while let b'0'..=b'9' = tri!(self.peek_or_null()) {
+            self.eat_char();
+        }
+
+        Ok(())
+    }
+
+    #[cfg(feature = "raw_value")]
+    fn deserialize_raw_value<V>(&mut self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        tri!(self.parse_whitespace());
+        self.read.begin_raw_buffering();
+        tri!(self.ignore_value());
+        self.read.end_raw_buffering(visitor)
+    }
+}
+
+impl FromStr for Number {
+    type Err = Error;
+
+    fn from_str(s: &str) -> result::Result<Self, Self::Err> {
+        Deserializer::from_str(s)
+            .parse_any_signed_number()
+            .map(Into::into)
+    }
+}
+
+#[cfg(not(feature = "float_roundtrip"))]
+static POW10: [f64; 309] = [
+    1e000, 1e001, 1e002, 1e003, 1e004, 1e005, 1e006, 1e007, 1e008, 1e009, //
+    1e010, 1e011, 1e012, 1e013, 1e014, 1e015, 1e016, 1e017, 1e018, 1e019, //
+    1e020, 1e021, 1e022, 1e023, 1e024, 1e025, 1e026, 1e027, 1e028, 1e029, //
+    1e030, 1e031, 1e032, 1e033, 1e034, 1e035, 1e036, 1e037, 1e038, 1e039, //
+    1e040, 1e041, 1e042, 1e043, 1e044, 1e045, 1e046, 1e047, 1e048, 1e049, //
+    1e050, 1e051, 1e052, 1e053, 1e054, 1e055, 1e056, 1e057, 1e058, 1e059, //
+    1e060, 1e061, 1e062, 1e063, 1e064, 1e065, 1e066, 1e067, 1e068, 1e069, //
+    1e070, 1e071, 1e072, 1e073, 1e074, 1e075, 1e076, 1e077, 1e078, 1e079, //
+    1e080, 1e081, 1e082, 1e083, 1e084, 1e085, 1e086, 1e087, 1e088, 1e089, //
+    1e090, 1e091, 1e092, 1e093, 1e094, 1e095, 1e096, 1e097, 1e098, 1e099, //
+    1e100, 1e101, 1e102, 1e103, 1e104, 1e105, 1e106, 1e107, 1e108, 1e109, //
+    1e110, 1e111, 1e112, 1e113, 1e114, 1e115, 1e116, 1e117, 1e118, 1e119, //
+    1e120, 1e121, 1e122, 1e123, 1e124, 1e125, 1e126, 1e127, 1e128, 1e129, //
+    1e130, 1e131, 1e132, 1e133, 1e134, 1e135, 1e136, 1e137, 1e138, 1e139, //
+    1e140, 1e141, 1e142, 1e143, 1e144, 1e145, 1e146, 1e147, 1e148, 1e149, //
+    1e150, 1e151, 1e152, 1e153, 1e154, 1e155, 1e156, 1e157, 1e158, 1e159, //
+    1e160, 1e161, 1e162, 1e163, 1e164, 1e165, 1e166, 1e167, 1e168, 1e169, //
+    1e170, 1e171, 1e172, 1e173, 1e174, 1e175, 1e176, 1e177, 1e178, 1e179, //
+    1e180, 1e181, 1e182, 1e183, 1e184, 1e185, 1e186, 1e187, 1e188, 1e189, //
+    1e190, 1e191, 1e192, 1e193, 1e194, 1e195, 1e196, 1e197, 1e198, 1e199, //
+    1e200, 1e201, 1e202, 1e203, 1e204, 1e205, 1e206, 1e207, 1e208, 1e209, //
+    1e210, 1e211, 1e212, 1e213, 1e214, 1e215, 1e216, 1e217, 1e218, 1e219, //
+    1e220, 1e221, 1e222, 1e223, 1e224, 1e225, 1e226, 1e227, 1e228, 1e229, //
+    1e230, 1e231, 1e232, 1e233, 1e234, 1e235, 1e236, 1e237, 1e238, 1e239, //
+    1e240, 1e241, 1e242, 1e243, 1e244, 1e245, 1e246, 1e247, 1e248, 1e249, //
+    1e250, 1e251, 1e252, 1e253, 1e254, 1e255, 1e256, 1e257, 1e258, 1e259, //
+    1e260, 1e261, 1e262, 1e263, 1e264, 1e265, 1e266, 1e267, 1e268, 1e269, //
+    1e270, 1e271, 1e272, 1e273, 1e274, 1e275, 1e276, 1e277, 1e278, 1e279, //
+    1e280, 1e281, 1e282, 1e283, 1e284, 1e285, 1e286, 1e287, 1e288, 1e289, //
+    1e290, 1e291, 1e292, 1e293, 1e294, 1e295, 1e296, 1e297, 1e298, 1e299, //
+    1e300, 1e301, 1e302, 1e303, 1e304, 1e305, 1e306, 1e307, 1e308,
+];
+
+macro_rules! deserialize_number {
+    ($method:ident) => {
+        deserialize_number!($method, deserialize_number);
+    };
+
+    ($method:ident, $using:ident) => {
+        fn $method<V>(self, visitor: V) -> Result<V::Value>
+        where
+            V: de::Visitor<'de>,
+        {
+            self.$using(visitor)
+        }
+    };
+}
+
+#[cfg(not(feature = "unbounded_depth"))]
+macro_rules! if_checking_recursion_limit {
+    ($($body:tt)*) => {
+        $($body)*
+    };
+}
+
+#[cfg(feature = "unbounded_depth")]
+macro_rules! if_checking_recursion_limit {
+    ($this:ident $($body:tt)*) => {
+        if !$this.disable_recursion_limit {
+            $this $($body)*
+        }
+    };
+}
+
+macro_rules! check_recursion {
+    ($this:ident $($body:tt)*) => {
+        if_checking_recursion_limit! {
+            $this.remaining_depth -= 1;
+            if $this.remaining_depth == 0 {
+                return Err($this.peek_error(ErrorCode::RecursionLimitExceeded));
+            }
+        }
+
+        $this $($body)*
+
+        if_checking_recursion_limit! {
+            $this.remaining_depth += 1;
+        }
+    };
+}
+
+impl<'de, 'a, R: Read<'de>> de::Deserializer<'de> for &'a mut Deserializer<R> {
+    type Error = Error;
+
+    #[inline]
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'n' => {
+                self.eat_char();
+                tri!(self.parse_ident(b"ull"));
+                visitor.visit_unit()
+            }
+            b't' => {
+                self.eat_char();
+                tri!(self.parse_ident(b"rue"));
+                visitor.visit_bool(true)
+            }
+            b'f' => {
+                self.eat_char();
+                tri!(self.parse_ident(b"alse"));
+                visitor.visit_bool(false)
+            }
+            b'-' => {
+                self.eat_char();
+                tri!(self.parse_any_number(false)).visit(visitor)
+            }
+            b'0'..=b'9' => tri!(self.parse_any_number(true)).visit(visitor),
+            b'"' => {
+                self.eat_char();
+                self.scratch.clear();
+                match tri!(self.read.parse_str(&mut self.scratch)) {
+                    Reference::Borrowed(s) => visitor.visit_borrowed_str(s),
+                    Reference::Copied(s) => visitor.visit_str(s),
+                }
+            }
+            b'[' => {
+                check_recursion! {
+                    self.eat_char();
+                    let ret = visitor.visit_seq(SeqAccess::new(self));
+                }
+
+                match (ret, self.end_seq()) {
+                    (Ok(ret), Ok(())) => Ok(ret),
+                    (Err(err), _) | (_, Err(err)) => Err(err),
+                }
+            }
+            b'{' => {
+                check_recursion! {
+                    self.eat_char();
+                    let ret = visitor.visit_map(MapAccess::new(self));
+                }
+
+                match (ret, self.end_map()) {
+                    (Ok(ret), Ok(())) => Ok(ret),
+                    (Err(err), _) | (_, Err(err)) => Err(err),
+                }
+            }
+            _ => Err(self.peek_error(ErrorCode::ExpectedSomeValue)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            // The de::Error impl creates errors with unknown line and column.
+            // Fill in the position here by looking at the current index in the
+            // input. There is no way to tell whether this should call `error`
+            // or `peek_error` so pick the one that seems correct more often.
+            // Worst case, the position is off by one character.
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b't' => {
+                self.eat_char();
+                tri!(self.parse_ident(b"rue"));
+                visitor.visit_bool(true)
+            }
+            b'f' => {
+                self.eat_char();
+                tri!(self.parse_ident(b"alse"));
+                visitor.visit_bool(false)
+            }
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    deserialize_number!(deserialize_i8);
+    deserialize_number!(deserialize_i16);
+    deserialize_number!(deserialize_i32);
+    deserialize_number!(deserialize_i64);
+    deserialize_number!(deserialize_u8);
+    deserialize_number!(deserialize_u16);
+    deserialize_number!(deserialize_u32);
+    deserialize_number!(deserialize_u64);
+    #[cfg(not(feature = "float_roundtrip"))]
+    deserialize_number!(deserialize_f32);
+    deserialize_number!(deserialize_f64);
+
+    #[cfg(feature = "float_roundtrip")]
+    deserialize_number!(deserialize_f32, do_deserialize_f32);
+    deserialize_number!(deserialize_i128, do_deserialize_i128);
+    deserialize_number!(deserialize_u128, do_deserialize_u128);
+
+    fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_str(visitor)
+    }
+
+    fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'"' => {
+                self.eat_char();
+                self.scratch.clear();
+                match tri!(self.read.parse_str(&mut self.scratch)) {
+                    Reference::Borrowed(s) => visitor.visit_borrowed_str(s),
+                    Reference::Copied(s) => visitor.visit_str(s),
+                }
+            }
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_str(visitor)
+    }
+
+    /// Parses a JSON string as bytes. Note that this function does not check
+    /// whether the bytes represent a valid UTF-8 string.
+    ///
+    /// The relevant part of the JSON specification is Section 8.2 of [RFC
+    /// 7159]:
+    ///
+    /// > When all the strings represented in a JSON text are composed entirely
+    /// > of Unicode characters (however escaped), then that JSON text is
+    /// > interoperable in the sense that all software implementations that
+    /// > parse it will agree on the contents of names and of string values in
+    /// > objects and arrays.
+    /// >
+    /// > However, the ABNF in this specification allows member names and string
+    /// > values to contain bit sequences that cannot encode Unicode characters;
+    /// > for example, "\uDEAD" (a single unpaired UTF-16 surrogate). Instances
+    /// > of this have been observed, for example, when a library truncates a
+    /// > UTF-16 string without checking whether the truncation split a
+    /// > surrogate pair.  The behavior of software that receives JSON texts
+    /// > containing such values is unpredictable; for example, implementations
+    /// > might return different values for the length of a string value or even
+    /// > suffer fatal runtime exceptions.
+    ///
+    /// [RFC 7159]: https://tools.ietf.org/html/rfc7159
+    ///
+    /// The behavior of serde_json is specified to fail on non-UTF-8 strings
+    /// when deserializing into Rust UTF-8 string types such as String, and
+    /// succeed with non-UTF-8 bytes when deserializing using this method.
+    ///
+    /// Escape sequences are processed as usual, and for `\uXXXX` escapes it is
+    /// still checked if the hex number represents a valid Unicode code point.
+    ///
+    /// # Examples
+    ///
+    /// You can use this to parse JSON strings containing invalid UTF-8 bytes,
+    /// or unpaired surrogates.
+    ///
+    /// ```
+    /// use serde_bytes::ByteBuf;
+    ///
+    /// fn look_at_bytes() -> Result<(), serde_json::Error> {
+    ///     let json_data = b"\"some bytes: \xe5\x00\xe5\"";
+    ///     let bytes: ByteBuf = serde_json::from_slice(json_data)?;
+    ///
+    ///     assert_eq!(b'\xe5', bytes[12]);
+    ///     assert_eq!(b'\0', bytes[13]);
+    ///     assert_eq!(b'\xe5', bytes[14]);
+    ///
+    ///     Ok(())
+    /// }
+    /// #
+    /// # look_at_bytes().unwrap();
+    /// ```
+    ///
+    /// Backslash escape sequences like `\n` are still interpreted and required
+    /// to be valid. `\u` escape sequences are required to represent a valid
+    /// Unicode code point or lone surrogate.
+    ///
+    /// ```
+    /// use serde_bytes::ByteBuf;
+    ///
+    /// fn look_at_bytes() -> Result<(), serde_json::Error> {
+    ///     let json_data = b"\"lone surrogate: \\uD801\"";
+    ///     let bytes: ByteBuf = serde_json::from_slice(json_data)?;
+    ///     let expected = b"lone surrogate: \xED\xA0\x81";
+    ///     assert_eq!(expected, bytes.as_slice());
+    ///     Ok(())
+    /// }
+    /// #
+    /// # look_at_bytes();
+    /// ```
+    fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'"' => {
+                self.eat_char();
+                self.scratch.clear();
+                match tri!(self.read.parse_str_raw(&mut self.scratch)) {
+                    Reference::Borrowed(b) => visitor.visit_borrowed_bytes(b),
+                    Reference::Copied(b) => visitor.visit_bytes(b),
+                }
+            }
+            b'[' => self.deserialize_seq(visitor),
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    #[inline]
+    fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_bytes(visitor)
+    }
+
+    /// Parses a `null` as a None, and any other values as a `Some(...)`.
+    #[inline]
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        match tri!(self.parse_whitespace()) {
+            Some(b'n') => {
+                self.eat_char();
+                tri!(self.parse_ident(b"ull"));
+                visitor.visit_none()
+            }
+            _ => visitor.visit_some(self),
+        }
+    }
+
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'n' => {
+                self.eat_char();
+                tri!(self.parse_ident(b"ull"));
+                visitor.visit_unit()
+            }
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_unit(visitor)
+    }
+
+    /// Parses a newtype struct as the underlying value.
+    #[inline]
+    fn deserialize_newtype_struct<V>(self, name: &str, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        #[cfg(feature = "raw_value")]
+        {
+            if name == crate::raw::TOKEN {
+                return self.deserialize_raw_value(visitor);
+            }
+        }
+
+        let _ = name;
+        visitor.visit_newtype_struct(self)
+    }
+
+    fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'[' => {
+                check_recursion! {
+                    self.eat_char();
+                    let ret = visitor.visit_seq(SeqAccess::new(self));
+                }
+
+                match (ret, self.end_seq()) {
+                    (Ok(ret), Ok(())) => Ok(ret),
+                    (Err(err), _) | (_, Err(err)) => Err(err),
+                }
+            }
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_seq(visitor)
+    }
+
+    fn deserialize_tuple_struct<V>(
+        self,
+        _name: &'static str,
+        _len: usize,
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_seq(visitor)
+    }
+
+    fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'{' => {
+                check_recursion! {
+                    self.eat_char();
+                    let ret = visitor.visit_map(MapAccess::new(self));
+                }
+
+                match (ret, self.end_map()) {
+                    (Ok(ret), Ok(())) => Ok(ret),
+                    (Err(err), _) | (_, Err(err)) => Err(err),
+                }
+            }
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    fn deserialize_struct<V>(
+        self,
+        _name: &'static str,
+        _fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        let peek = match tri!(self.parse_whitespace()) {
+            Some(b) => b,
+            None => {
+                return Err(self.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b'[' => {
+                check_recursion! {
+                    self.eat_char();
+                    let ret = visitor.visit_seq(SeqAccess::new(self));
+                }
+
+                match (ret, self.end_seq()) {
+                    (Ok(ret), Ok(())) => Ok(ret),
+                    (Err(err), _) | (_, Err(err)) => Err(err),
+                }
+            }
+            b'{' => {
+                check_recursion! {
+                    self.eat_char();
+                    let ret = visitor.visit_map(MapAccess::new(self));
+                }
+
+                match (ret, self.end_map()) {
+                    (Ok(ret), Ok(())) => Ok(ret),
+                    (Err(err), _) | (_, Err(err)) => Err(err),
+                }
+            }
+            _ => Err(self.peek_invalid_type(&visitor)),
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.fix_position(err)),
+        }
+    }
+
+    /// Parses an enum as an object like `{"$KEY":$VALUE}`, where $VALUE is either a straight
+    /// value, a `[..]`, or a `{..}`.
+    #[inline]
+    fn deserialize_enum<V>(
+        self,
+        _name: &str,
+        _variants: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        match tri!(self.parse_whitespace()) {
+            Some(b'{') => {
+                check_recursion! {
+                    self.eat_char();
+                    let value = tri!(visitor.visit_enum(VariantAccess::new(self)));
+                }
+
+                match tri!(self.parse_whitespace()) {
+                    Some(b'}') => {
+                        self.eat_char();
+                        Ok(value)
+                    }
+                    Some(_) => Err(self.error(ErrorCode::ExpectedSomeValue)),
+                    None => Err(self.error(ErrorCode::EofWhileParsingObject)),
+                }
+            }
+            Some(b'"') => visitor.visit_enum(UnitVariantAccess::new(self)),
+            Some(_) => Err(self.peek_error(ErrorCode::ExpectedSomeValue)),
+            None => Err(self.peek_error(ErrorCode::EofWhileParsingValue)),
+        }
+    }
+
+    fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_str(visitor)
+    }
+
+    fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        tri!(self.ignore_value());
+        visitor.visit_unit()
+    }
+}
+
+struct SeqAccess<'a, R: 'a> {
+    de: &'a mut Deserializer<R>,
+    first: bool,
+}
+
+impl<'a, R: 'a> SeqAccess<'a, R> {
+    fn new(de: &'a mut Deserializer<R>) -> Self {
+        SeqAccess { de, first: true }
+    }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::SeqAccess<'de> for SeqAccess<'a, R> {
+    type Error = Error;
+
+    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+    where
+        T: de::DeserializeSeed<'de>,
+    {
+        let peek = match tri!(self.de.parse_whitespace()) {
+            Some(b']') => {
+                return Ok(None);
+            }
+            Some(b',') if !self.first => {
+                self.de.eat_char();
+                tri!(self.de.parse_whitespace())
+            }
+            Some(b) => {
+                if self.first {
+                    self.first = false;
+                    Some(b)
+                } else {
+                    return Err(self.de.peek_error(ErrorCode::ExpectedListCommaOrEnd));
+                }
+            }
+            None => {
+                return Err(self.de.peek_error(ErrorCode::EofWhileParsingList));
+            }
+        };
+
+        match peek {
+            Some(b']') => Err(self.de.peek_error(ErrorCode::TrailingComma)),
+            Some(_) => Ok(Some(tri!(seed.deserialize(&mut *self.de)))),
+            None => Err(self.de.peek_error(ErrorCode::EofWhileParsingValue)),
+        }
+    }
+}
+
+struct MapAccess<'a, R: 'a> {
+    de: &'a mut Deserializer<R>,
+    first: bool,
+}
+
+impl<'a, R: 'a> MapAccess<'a, R> {
+    fn new(de: &'a mut Deserializer<R>) -> Self {
+        MapAccess { de, first: true }
+    }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::MapAccess<'de> for MapAccess<'a, R> {
+    type Error = Error;
+
+    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
+    where
+        K: de::DeserializeSeed<'de>,
+    {
+        let peek = match tri!(self.de.parse_whitespace()) {
+            Some(b'}') => {
+                return Ok(None);
+            }
+            Some(b',') if !self.first => {
+                self.de.eat_char();
+                tri!(self.de.parse_whitespace())
+            }
+            Some(b) => {
+                if self.first {
+                    self.first = false;
+                    Some(b)
+                } else {
+                    return Err(self.de.peek_error(ErrorCode::ExpectedObjectCommaOrEnd));
+                }
+            }
+            None => {
+                return Err(self.de.peek_error(ErrorCode::EofWhileParsingObject));
+            }
+        };
+
+        match peek {
+            Some(b'"') => seed.deserialize(MapKey { de: &mut *self.de }).map(Some),
+            Some(b'}') => Err(self.de.peek_error(ErrorCode::TrailingComma)),
+            Some(_) => Err(self.de.peek_error(ErrorCode::KeyMustBeAString)),
+            None => Err(self.de.peek_error(ErrorCode::EofWhileParsingValue)),
+        }
+    }
+
+    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value>
+    where
+        V: de::DeserializeSeed<'de>,
+    {
+        tri!(self.de.parse_object_colon());
+
+        seed.deserialize(&mut *self.de)
+    }
+}
+
+struct VariantAccess<'a, R: 'a> {
+    de: &'a mut Deserializer<R>,
+}
+
+impl<'a, R: 'a> VariantAccess<'a, R> {
+    fn new(de: &'a mut Deserializer<R>) -> Self {
+        VariantAccess { de }
+    }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::EnumAccess<'de> for VariantAccess<'a, R> {
+    type Error = Error;
+    type Variant = Self;
+
+    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self)>
+    where
+        V: de::DeserializeSeed<'de>,
+    {
+        let val = tri!(seed.deserialize(&mut *self.de));
+        tri!(self.de.parse_object_colon());
+        Ok((val, self))
+    }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::VariantAccess<'de> for VariantAccess<'a, R> {
+    type Error = Error;
+
+    fn unit_variant(self) -> Result<()> {
+        de::Deserialize::deserialize(self.de)
+    }
+
+    fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value>
+    where
+        T: de::DeserializeSeed<'de>,
+    {
+        seed.deserialize(self.de)
+    }
+
+    fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        de::Deserializer::deserialize_seq(self.de, visitor)
+    }
+
+    fn struct_variant<V>(self, fields: &'static [&'static str], visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        de::Deserializer::deserialize_struct(self.de, "", fields, visitor)
+    }
+}
+
+struct UnitVariantAccess<'a, R: 'a> {
+    de: &'a mut Deserializer<R>,
+}
+
+impl<'a, R: 'a> UnitVariantAccess<'a, R> {
+    fn new(de: &'a mut Deserializer<R>) -> Self {
+        UnitVariantAccess { de }
+    }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::EnumAccess<'de> for UnitVariantAccess<'a, R> {
+    type Error = Error;
+    type Variant = Self;
+
+    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self)>
+    where
+        V: de::DeserializeSeed<'de>,
+    {
+        let variant = tri!(seed.deserialize(&mut *self.de));
+        Ok((variant, self))
+    }
+}
+
+impl<'de, 'a, R: Read<'de> + 'a> de::VariantAccess<'de> for UnitVariantAccess<'a, R> {
+    type Error = Error;
+
+    fn unit_variant(self) -> Result<()> {
+        Ok(())
+    }
+
+    fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value>
+    where
+        T: de::DeserializeSeed<'de>,
+    {
+        Err(de::Error::invalid_type(
+            Unexpected::UnitVariant,
+            &"newtype variant",
+        ))
+    }
+
+    fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        Err(de::Error::invalid_type(
+            Unexpected::UnitVariant,
+            &"tuple variant",
+        ))
+    }
+
+    fn struct_variant<V>(self, _fields: &'static [&'static str], _visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        Err(de::Error::invalid_type(
+            Unexpected::UnitVariant,
+            &"struct variant",
+        ))
+    }
+}
+
+/// Only deserialize from this after peeking a '"' byte! Otherwise it may
+/// deserialize invalid JSON successfully.
+struct MapKey<'a, R: 'a> {
+    de: &'a mut Deserializer<R>,
+}
+
+macro_rules! deserialize_numeric_key {
+    ($method:ident) => {
+        fn $method<V>(self, visitor: V) -> Result<V::Value>
+        where
+            V: de::Visitor<'de>,
+        {
+            self.deserialize_number(visitor)
+        }
+    };
+
+    ($method:ident, $delegate:ident) => {
+        fn $method<V>(self, visitor: V) -> Result<V::Value>
+        where
+            V: de::Visitor<'de>,
+        {
+            self.de.eat_char();
+
+            match tri!(self.de.peek()) {
+                Some(b'0'..=b'9' | b'-') => {}
+                _ => return Err(self.de.error(ErrorCode::ExpectedNumericKey)),
+            }
+
+            let value = tri!(self.de.$delegate(visitor));
+
+            match tri!(self.de.peek()) {
+                Some(b'"') => self.de.eat_char(),
+                _ => return Err(self.de.peek_error(ErrorCode::ExpectedDoubleQuote)),
+            }
+
+            Ok(value)
+        }
+    };
+}
+
+impl<'de, 'a, R> MapKey<'a, R>
+where
+    R: Read<'de>,
+{
+    deserialize_numeric_key!(deserialize_number, deserialize_number);
+}
+
+impl<'de, 'a, R> de::Deserializer<'de> for MapKey<'a, R>
+where
+    R: Read<'de>,
+{
+    type Error = Error;
+
+    #[inline]
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.de.eat_char();
+        self.de.scratch.clear();
+        match tri!(self.de.read.parse_str(&mut self.de.scratch)) {
+            Reference::Borrowed(s) => visitor.visit_borrowed_str(s),
+            Reference::Copied(s) => visitor.visit_str(s),
+        }
+    }
+
+    deserialize_numeric_key!(deserialize_i8);
+    deserialize_numeric_key!(deserialize_i16);
+    deserialize_numeric_key!(deserialize_i32);
+    deserialize_numeric_key!(deserialize_i64);
+    deserialize_numeric_key!(deserialize_i128, deserialize_i128);
+    deserialize_numeric_key!(deserialize_u8);
+    deserialize_numeric_key!(deserialize_u16);
+    deserialize_numeric_key!(deserialize_u32);
+    deserialize_numeric_key!(deserialize_u64);
+    deserialize_numeric_key!(deserialize_u128, deserialize_u128);
+    #[cfg(not(feature = "float_roundtrip"))]
+    deserialize_numeric_key!(deserialize_f32);
+    #[cfg(feature = "float_roundtrip")]
+    deserialize_numeric_key!(deserialize_f32, deserialize_f32);
+    deserialize_numeric_key!(deserialize_f64);
+
+    fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.de.eat_char();
+
+        let peek = match tri!(self.de.next_char()) {
+            Some(b) => b,
+            None => {
+                return Err(self.de.peek_error(ErrorCode::EofWhileParsingValue));
+            }
+        };
+
+        let value = match peek {
+            b't' => {
+                tri!(self.de.parse_ident(b"rue\""));
+                visitor.visit_bool(true)
+            }
+            b'f' => {
+                tri!(self.de.parse_ident(b"alse\""));
+                visitor.visit_bool(false)
+            }
+            _ => {
+                self.de.scratch.clear();
+                let s = tri!(self.de.read.parse_str(&mut self.de.scratch));
+                Err(de::Error::invalid_type(Unexpected::Str(&s), &visitor))
+            }
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(err) => Err(self.de.fix_position(err)),
+        }
+    }
+
+    #[inline]
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        // Map keys cannot be null.
+        visitor.visit_some(self)
+    }
+
+    #[inline]
+    fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        #[cfg(feature = "raw_value")]
+        {
+            if name == crate::raw::TOKEN {
+                return self.de.deserialize_raw_value(visitor);
+            }
+        }
+
+        let _ = name;
+        visitor.visit_newtype_struct(self)
+    }
+
+    #[inline]
+    fn deserialize_enum<V>(
+        self,
+        name: &'static str,
+        variants: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.de.deserialize_enum(name, variants, visitor)
+    }
+
+    #[inline]
+    fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.de.deserialize_bytes(visitor)
+    }
+
+    #[inline]
+    fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.de.deserialize_bytes(visitor)
+    }
+
+    forward_to_deserialize_any! {
+        char str string unit unit_struct seq tuple tuple_struct map struct
+        identifier ignored_any
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+/// Iterator that deserializes a stream into multiple JSON values.
+///
+/// A stream deserializer can be created from any JSON deserializer using the
+/// `Deserializer::into_iter` method.
+///
+/// The data can consist of any JSON value. Values need to be a self-delineating value e.g.
+/// arrays, objects, or strings, or be followed by whitespace or a self-delineating value.
+///
+/// ```
+/// use serde_json::{Deserializer, Value};
+///
+/// fn main() {
+///     let data = "{\"k\": 3}1\"cool\"\"stuff\" 3{}  [0, 1, 2]";
+///
+///     let stream = Deserializer::from_str(data).into_iter::<Value>();
+///
+///     for value in stream {
+///         println!("{}", value.unwrap());
+///     }
+/// }
+/// ```
+pub struct StreamDeserializer<'de, R, T> {
+    de: Deserializer<R>,
+    offset: usize,
+    failed: bool,
+    output: PhantomData<T>,
+    lifetime: PhantomData<&'de ()>,
+}
+
+impl<'de, R, T> StreamDeserializer<'de, R, T>
+where
+    R: read::Read<'de>,
+    T: de::Deserialize<'de>,
+{
+    /// Create a JSON stream deserializer from one of the possible serde_json
+    /// input sources.
+    ///
+    /// Typically it is more convenient to use one of these methods instead:
+    ///
+    ///   - Deserializer::from_str(...).into_iter()
+    ///   - Deserializer::from_slice(...).into_iter()
+    ///   - Deserializer::from_reader(...).into_iter()
+    pub fn new(read: R) -> Self {
+        let offset = read.byte_offset();
+        StreamDeserializer {
+            de: Deserializer::new(read),
+            offset,
+            failed: false,
+            output: PhantomData,
+            lifetime: PhantomData,
+        }
+    }
+
+    /// Returns the number of bytes so far deserialized into a successful `T`.
+    ///
+    /// If a stream deserializer returns an EOF error, new data can be joined to
+    /// `old_data[stream.byte_offset()..]` to try again.
+    ///
+    /// ```
+    /// let data = b"[0] [1] [";
+    ///
+    /// let de = serde_json::Deserializer::from_slice(data);
+    /// let mut stream = de.into_iter::<Vec<i32>>();
+    /// assert_eq!(0, stream.byte_offset());
+    ///
+    /// println!("{:?}", stream.next()); // [0]
+    /// assert_eq!(3, stream.byte_offset());
+    ///
+    /// println!("{:?}", stream.next()); // [1]
+    /// assert_eq!(7, stream.byte_offset());
+    ///
+    /// println!("{:?}", stream.next()); // error
+    /// assert_eq!(8, stream.byte_offset());
+    ///
+    /// // If err.is_eof(), can join the remaining data to new data and continue.
+    /// let remaining = &data[stream.byte_offset()..];
+    /// ```
+    ///
+    /// *Note:* In the future this method may be changed to return the number of
+    /// bytes so far deserialized into a successful T *or* syntactically valid
+    /// JSON skipped over due to a type error. See [serde-rs/json#70] for an
+    /// example illustrating this.
+    ///
+    /// [serde-rs/json#70]: https://github.com/serde-rs/json/issues/70
+    pub fn byte_offset(&self) -> usize {
+        self.offset
+    }
+
+    fn peek_end_of_value(&mut self) -> Result<()> {
+        match tri!(self.de.peek()) {
+            Some(b' ' | b'\n' | b'\t' | b'\r' | b'"' | b'[' | b']' | b'{' | b'}' | b',' | b':')
+            | None => Ok(()),
+            Some(_) => {
+                let position = self.de.read.peek_position();
+                Err(Error::syntax(
+                    ErrorCode::TrailingCharacters,
+                    position.line,
+                    position.column,
+                ))
+            }
+        }
+    }
+}
+
+impl<'de, R, T> Iterator for StreamDeserializer<'de, R, T>
+where
+    R: Read<'de>,
+    T: de::Deserialize<'de>,
+{
+    type Item = Result<T>;
+
+    fn next(&mut self) -> Option<Result<T>> {
+        if R::should_early_return_if_failed && self.failed {
+            return None;
+        }
+
+        // skip whitespaces, if any
+        // this helps with trailing whitespaces, since whitespaces between
+        // values are handled for us.
+        match self.de.parse_whitespace() {
+            Ok(None) => {
+                self.offset = self.de.read.byte_offset();
+                None
+            }
+            Ok(Some(b)) => {
+                // If the value does not have a clear way to show the end of the value
+                // (like numbers, null, true etc.) we have to look for whitespace or
+                // the beginning of a self-delineated value.
+                let self_delineated_value = match b {
+                    b'[' | b'"' | b'{' => true,
+                    _ => false,
+                };
+                self.offset = self.de.read.byte_offset();
+                let result = de::Deserialize::deserialize(&mut self.de);
+
+                Some(match result {
+                    Ok(value) => {
+                        self.offset = self.de.read.byte_offset();
+                        if self_delineated_value {
+                            Ok(value)
+                        } else {
+                            self.peek_end_of_value().map(|()| value)
+                        }
+                    }
+                    Err(e) => {
+                        self.de.read.set_failed(&mut self.failed);
+                        Err(e)
+                    }
+                })
+            }
+            Err(e) => {
+                self.de.read.set_failed(&mut self.failed);
+                Some(Err(e))
+            }
+        }
+    }
+}
+
+impl<'de, R, T> FusedIterator for StreamDeserializer<'de, R, T>
+where
+    R: Read<'de> + Fused,
+    T: de::Deserialize<'de>,
+{
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+fn from_trait<'de, R, T>(read: R) -> Result<T>
+where
+    R: Read<'de>,
+    T: de::Deserialize<'de>,
+{
+    let mut de = Deserializer::new(read);
+    let value = tri!(de::Deserialize::deserialize(&mut de));
+
+    // Make sure the whole stream has been consumed.
+    tri!(de.end());
+    Ok(value)
+}
+
+/// Deserialize an instance of type `T` from an I/O stream of JSON.
+///
+/// The content of the I/O stream is deserialized directly from the stream
+/// without being buffered in memory by serde_json.
+///
+/// When reading from a source against which short reads are not efficient, such
+/// as a [`File`], you will want to apply your own buffering because serde_json
+/// will not buffer the input. See [`std::io::BufReader`].
+///
+/// It is expected that the input stream ends after the deserialized object.
+/// If the stream does not end, such as in the case of a persistent socket connection,
+/// this function will not return. It is possible instead to deserialize from a prefix of an input
+/// stream without looking for EOF by managing your own [`Deserializer`].
+///
+/// Note that counter to intuition, this function is usually slower than
+/// reading a file completely into memory and then applying [`from_str`]
+/// or [`from_slice`] on it. See [issue #160].
+///
+/// [`File`]: https://doc.rust-lang.org/std/fs/struct.File.html
+/// [`std::io::BufReader`]: https://doc.rust-lang.org/std/io/struct.BufReader.html
+/// [`from_str`]: ./fn.from_str.html
+/// [`from_slice`]: ./fn.from_slice.html
+/// [issue #160]: https://github.com/serde-rs/json/issues/160
+///
+/// # Example
+///
+/// Reading the contents of a file.
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// use std::error::Error;
+/// use std::fs::File;
+/// use std::io::BufReader;
+/// use std::path::Path;
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+///     fingerprint: String,
+///     location: String,
+/// }
+///
+/// fn read_user_from_file<P: AsRef<Path>>(path: P) -> Result<User, Box<dyn Error>> {
+///     // Open the file in read-only mode with buffer.
+///     let file = File::open(path)?;
+///     let reader = BufReader::new(file);
+///
+///     // Read the JSON contents of the file as an instance of `User`.
+///     let u = serde_json::from_reader(reader)?;
+///
+///     // Return the `User`.
+///     Ok(u)
+/// }
+///
+/// fn main() {
+/// # }
+/// # fn fake_main() {
+///     let u = read_user_from_file("test.json").unwrap();
+///     println!("{:#?}", u);
+/// }
+/// ```
+///
+/// Reading from a persistent socket connection.
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// use std::error::Error;
+/// use std::net::{TcpListener, TcpStream};
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+///     fingerprint: String,
+///     location: String,
+/// }
+///
+/// fn read_user_from_stream(tcp_stream: TcpStream) -> Result<User, Box<dyn Error>> {
+///     let mut de = serde_json::Deserializer::from_reader(tcp_stream);
+///     let u = User::deserialize(&mut de)?;
+///
+///     Ok(u)
+/// }
+///
+/// fn main() {
+/// # }
+/// # fn fake_main() {
+///     let listener = TcpListener::bind("127.0.0.1:4000").unwrap();
+///
+///     for stream in listener.incoming() {
+///         println!("{:#?}", read_user_from_stream(stream.unwrap()));
+///     }
+/// }
+/// ```
+///
+/// # Errors
+///
+/// This conversion can fail if the structure of the input does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the input
+/// contains something other than a JSON map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the JSON map or some number is too big to fit in the expected primitive
+/// type.
+#[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+pub fn from_reader<R, T>(rdr: R) -> Result<T>
+where
+    R: crate::io::Read,
+    T: de::DeserializeOwned,
+{
+    from_trait(read::IoRead::new(rdr))
+}
+
+/// Deserialize an instance of type `T` from bytes of JSON text.
+///
+/// # Example
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+///     fingerprint: String,
+///     location: String,
+/// }
+///
+/// fn main() {
+///     // The type of `j` is `&[u8]`
+///     let j = b"
+///         {
+///             \"fingerprint\": \"0xF9BA143B95FF6D82\",
+///             \"location\": \"Menlo Park, CA\"
+///         }";
+///
+///     let u: User = serde_json::from_slice(j).unwrap();
+///     println!("{:#?}", u);
+/// }
+/// ```
+///
+/// # Errors
+///
+/// This conversion can fail if the structure of the input does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the input
+/// contains something other than a JSON map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the JSON map or some number is too big to fit in the expected primitive
+/// type.
+pub fn from_slice<'a, T>(v: &'a [u8]) -> Result<T>
+where
+    T: de::Deserialize<'a>,
+{
+    from_trait(read::SliceRead::new(v))
+}
+
+/// Deserialize an instance of type `T` from a string of JSON text.
+///
+/// # Example
+///
+/// ```
+/// use serde::Deserialize;
+///
+/// #[derive(Deserialize, Debug)]
+/// struct User {
+///     fingerprint: String,
+///     location: String,
+/// }
+///
+/// fn main() {
+///     // The type of `j` is `&str`
+///     let j = "
+///         {
+///             \"fingerprint\": \"0xF9BA143B95FF6D82\",
+///             \"location\": \"Menlo Park, CA\"
+///         }";
+///
+///     let u: User = serde_json::from_str(j).unwrap();
+///     println!("{:#?}", u);
+/// }
+/// ```
+///
+/// # Errors
+///
+/// This conversion can fail if the structure of the input does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the input
+/// contains something other than a JSON map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the JSON map or some number is too big to fit in the expected primitive
+/// type.
+pub fn from_str<'a, T>(s: &'a str) -> Result<T>
+where
+    T: de::Deserialize<'a>,
+{
+    from_trait(read::StrRead::new(s))
+}