android/vendor/smol_str-0.2.0/src/lib.rs - toolchain/cargo-deny - Git at Google

 #![no_std]
 extern crate alloc;

 use alloc::{
     borrow::Cow,
     boxed::Box,
     string::{String, ToString},
     sync::Arc,
 };
 use core::{
     borrow::Borrow,
     cmp::{self, Ordering},
     convert::Infallible,
     fmt, hash, iter,
     mem::transmute,
     ops::Deref,
     str::FromStr,
 };

 /// A `SmolStr` is a string type that has the following properties:
 ///
 /// * `size_of::<SmolStr>() == 24 (therefor == size_of::<String>() on 64 bit platforms)
 /// * `Clone` is `O(1)`
 /// * Strings are stack-allocated if they are:
 ///     * Up to 23 bytes long
 ///     * Longer than 23 bytes, but substrings of `WS` (see below). Such strings consist
 ///     solely of consecutive newlines, followed by consecutive spaces
 /// * If a string does not satisfy the aforementioned conditions, it is heap-allocated
 ///
 /// Unlike `String`, however, `SmolStr` is immutable. The primary use case for
 /// `SmolStr` is a good enough default storage for tokens of typical programming
 /// languages. Strings consisting of a series of newlines, followed by a series of
 /// whitespace are a typical pattern in computer programs because of indentation.
 /// Note that a specialized interner might be a better solution for some use cases.
 ///
 /// `WS`: A string of 32 newlines followed by 128 spaces.
 #[derive(Clone)]
 pub struct SmolStr(Repr);

 impl SmolStr {
     #[deprecated = "Use `new_inline` instead"]
     pub const fn new_inline_from_ascii(len: usize, bytes: &[u8]) -> SmolStr {
         let _len_is_short = [(); INLINE_CAP + 1][len];

         const ZEROS: &[u8] = &[0; INLINE_CAP];

         let mut buf = [0; INLINE_CAP];
         macro_rules! s {
             ($($idx:literal),*) => ( $(s!(set $idx);)* );
             (set $idx:literal) => ({
                 let src: &[u8] = [ZEROS, bytes][($idx < len) as usize];
                 let byte = src[$idx];
                 let _is_ascii = [(); 128][byte as usize];
                 buf[$idx] = byte
             });
         }
         s!(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22);
         SmolStr(Repr::Inline {
             len: unsafe { transmute(len as u8) },
             buf,
         })
     }

     /// Constructs inline variant of `SmolStr`.
     ///
     /// Panics if `text.len() > 23`.
     #[inline]
     pub const fn new_inline(text: &str) -> SmolStr {
         let mut buf = [0; INLINE_CAP];
         let mut i = 0;
         while i < text.len() {
             buf[i] = text.as_bytes()[i];
             i += 1
         }
         SmolStr(Repr::Inline {
             len: unsafe { transmute(text.len() as u8) },
             buf,
         })
     }

     pub fn new<T>(text: T) -> SmolStr
     where
         T: AsRef<str>,
     {
         SmolStr(Repr::new(text))
     }

     #[inline(always)]
     pub fn as_str(&self) -> &str {
         self.0.as_str()
     }

     #[inline(always)]
     pub fn to_string(&self) -> String {
         self.as_str().to_string()
     }

     #[inline(always)]
     pub fn len(&self) -> usize {
         self.0.len()
     }

     #[inline(always)]
     pub fn is_empty(&self) -> bool {
         self.0.is_empty()
     }

     #[inline(always)]
     pub fn is_heap_allocated(&self) -> bool {
         match self.0 {
             Repr::Heap(..) => true,
             _ => false,
         }
     }

     fn from_char_iter<I: iter::Iterator<Item = char>>(mut iter: I) -> SmolStr {
         let (min_size, _) = iter.size_hint();
         if min_size > INLINE_CAP {
             let heap: String = iter.collect();
             return SmolStr(Repr::Heap(heap.into_boxed_str().into()));
         }
         let mut len = 0;
         let mut buf = [0u8; INLINE_CAP];
         while let Some(ch) = iter.next() {
             let size = ch.len_utf8();
             if size + len > INLINE_CAP {
                 let (min_remaining, _) = iter.size_hint();
                 let mut heap = String::with_capacity(size + len + min_remaining);
                 heap.push_str(core::str::from_utf8(&buf[..len]).unwrap());
                 heap.push(ch);
                 heap.extend(iter);
                 return SmolStr(Repr::Heap(heap.into_boxed_str().into()));
             }
             ch.encode_utf8(&mut buf[len..]);
             len += size;
         }
         SmolStr(Repr::Inline {
             len: unsafe { transmute(len as u8) },
             buf,
         })
     }
 }

 impl Default for SmolStr {
     fn default() -> SmolStr {
         SmolStr::new("")
     }
 }

 impl Deref for SmolStr {
     type Target = str;

     fn deref(&self) -> &str {
         self.as_str()
     }
 }

 impl PartialEq<SmolStr> for SmolStr {
     fn eq(&self, other: &SmolStr) -> bool {
         self.as_str() == other.as_str()
     }
 }

 impl Eq for SmolStr {}

 impl PartialEq<str> for SmolStr {
     fn eq(&self, other: &str) -> bool {
         self.as_str() == other
     }
 }

 impl PartialEq<SmolStr> for str {
     fn eq(&self, other: &SmolStr) -> bool {
         other == self
     }
 }

 impl<'a> PartialEq<&'a str> for SmolStr {
     fn eq(&self, other: &&'a str) -> bool {
         self == *other
     }
 }

 impl<'a> PartialEq<SmolStr> for &'a str {
     fn eq(&self, other: &SmolStr) -> bool {
         *self == other
     }
 }

 impl PartialEq<String> for SmolStr {
     fn eq(&self, other: &String) -> bool {
         self.as_str() == other
     }
 }

 impl PartialEq<SmolStr> for String {
     fn eq(&self, other: &SmolStr) -> bool {
         other == self
     }
 }

 impl<'a> PartialEq<&'a String> for SmolStr {
     fn eq(&self, other: &&'a String) -> bool {
         self == *other
     }
 }

 impl<'a> PartialEq<SmolStr> for &'a String {
     fn eq(&self, other: &SmolStr) -> bool {
         *self == other
     }
 }

 impl Ord for SmolStr {
     fn cmp(&self, other: &SmolStr) -> Ordering {
         self.as_str().cmp(other.as_str())
     }
 }

 impl PartialOrd for SmolStr {
     fn partial_cmp(&self, other: &SmolStr) -> Option<Ordering> {
         Some(self.cmp(other))
     }
 }

 impl hash::Hash for SmolStr {
     fn hash<H: hash::Hasher>(&self, hasher: &mut H) {
         self.as_str().hash(hasher)
     }
 }

 impl fmt::Debug for SmolStr {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         fmt::Debug::fmt(self.as_str(), f)
     }
 }

 impl fmt::Display for SmolStr {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         fmt::Display::fmt(self.as_str(), f)
     }
 }

 impl iter::FromIterator<char> for SmolStr {
     fn from_iter<I: iter::IntoIterator<Item = char>>(iter: I) -> SmolStr {
         let iter = iter.into_iter();
         Self::from_char_iter(iter)
     }
 }

 fn build_from_str_iter<T>(mut iter: impl Iterator<Item = T>) -> SmolStr
 where
     T: AsRef<str>,
     String: iter::Extend<T>,
 {
     let mut len = 0;
     let mut buf = [0u8; INLINE_CAP];
     while let Some(slice) = iter.next() {
         let slice = slice.as_ref();
         let size = slice.len();
         if size + len > INLINE_CAP {
             let mut heap = String::with_capacity(size + len);
             heap.push_str(core::str::from_utf8(&buf[..len]).unwrap());
             heap.push_str(&slice);
             heap.extend(iter);
             return SmolStr(Repr::Heap(heap.into_boxed_str().into()));
         }
         (&mut buf[len..][..size]).copy_from_slice(slice.as_bytes());
         len += size;
     }
     SmolStr(Repr::Inline {
         len: unsafe { transmute(len as u8) },
         buf,
     })
 }

 impl iter::FromIterator<String> for SmolStr {
     fn from_iter<I: iter::IntoIterator<Item = String>>(iter: I) -> SmolStr {
         build_from_str_iter(iter.into_iter())
     }
 }

 impl<'a> iter::FromIterator<&'a String> for SmolStr {
     fn from_iter<I: iter::IntoIterator<Item = &'a String>>(iter: I) -> SmolStr {
         SmolStr::from_iter(iter.into_iter().map(|x| x.as_str()))
     }
 }

 impl<'a> iter::FromIterator<&'a str> for SmolStr {
     fn from_iter<I: iter::IntoIterator<Item = &'a str>>(iter: I) -> SmolStr {
         build_from_str_iter(iter.into_iter())
     }
 }

 impl AsRef<str> for SmolStr {
     #[inline(always)]
     fn as_ref(&self) -> &str {
         self.as_str()
     }
 }

 impl From<&str> for SmolStr {
     #[inline]
     fn from(s: &str) -> SmolStr {
         SmolStr::new(s)
     }
 }

 impl From<&mut str> for SmolStr {
     #[inline]
     fn from(s: &mut str) -> SmolStr {
         SmolStr::new(s)
     }
 }

 impl From<&String> for SmolStr {
     #[inline]
     fn from(s: &String) -> SmolStr {
         SmolStr::new(s)
     }
 }

 impl From<String> for SmolStr {
     #[inline(always)]
     fn from(text: String) -> Self {
         Self::new(text)
     }
 }

 impl From<Box<str>> for SmolStr {
     #[inline]
     fn from(s: Box<str>) -> SmolStr {
         SmolStr::new(s)
     }
 }

 impl<'a> From<Cow<'a, str>> for SmolStr {
     #[inline]
     fn from(s: Cow<'a, str>) -> SmolStr {
         SmolStr::new(s)
     }
 }

 impl From<SmolStr> for String {
     #[inline(always)]
     fn from(text: SmolStr) -> Self {
         text.as_str().into()
     }
 }

 impl Borrow<str> for SmolStr {
     #[inline(always)]
     fn borrow(&self) -> &str {
         self.as_str()
     }
 }

 impl FromStr for SmolStr {
     type Err = Infallible;

     #[inline]
     fn from_str(s: &str) -> Result<SmolStr, Self::Err> {
         Ok(SmolStr::from(s))
     }
 }

 #[cfg(feature = "arbitrary")]
 impl<'a> arbitrary::Arbitrary<'a> for SmolStr {
     fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> Result<Self, arbitrary::Error> {
         let s = <&str>::arbitrary(u)?;
         Ok(SmolStr::new(s))
     }
 }

 const INLINE_CAP: usize = 23;
 const N_NEWLINES: usize = 32;
 const N_SPACES: usize = 128;
 const WS: &str =
     "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n                                                                                                                                ";

 #[derive(Clone, Copy, Debug)]
 #[repr(u8)]
 enum InlineSize {
     _V0 = 0,
     _V1,
     _V2,
     _V3,
     _V4,
     _V5,
     _V6,
     _V7,
     _V8,
     _V9,
     _V10,
     _V11,
     _V12,
     _V13,
     _V14,
     _V15,
     _V16,
     _V17,
     _V18,
     _V19,
     _V20,
     _V21,
     _V22,
     _V23,
 }

 #[derive(Clone, Debug)]
 enum Repr {
     Heap(Arc<str>),
     Inline {
         len: InlineSize,
         buf: [u8; INLINE_CAP],
     },
     Substring {
         newlines: usize,
         spaces: usize,
     },
 }

 impl Repr {
     fn new<T>(text: T) -> Self
     where
         T: AsRef<str>,
     {
         {
             let text = text.as_ref();

             let len = text.len();
             if len <= INLINE_CAP {
                 let mut buf = [0; INLINE_CAP];
                 buf[..len].copy_from_slice(text.as_bytes());
                 return Repr::Inline {
                     len: unsafe { transmute(len as u8) },
                     buf,
                 };
             }

             if len <= N_NEWLINES + N_SPACES {
                 let bytes = text.as_bytes();
                 let possible_newline_count = cmp::min(len, N_NEWLINES);
                 let newlines = bytes[..possible_newline_count]
                     .iter()
                     .take_while(|&&b| b == b'\n')
                     .count();
                 let possible_space_count = len - newlines;
                 if possible_space_count <= N_SPACES && bytes[newlines..].iter().all(|&b| b == b' ')
                 {
                     let spaces = possible_space_count;
                     return Repr::Substring { newlines, spaces };
                 }
             }
         }

         Repr::Heap(text.as_ref().into())
     }

     #[inline(always)]
     fn len(&self) -> usize {
         match self {
             Repr::Heap(data) => data.len(),
             Repr::Inline { len, .. } => *len as usize,
             Repr::Substring { newlines, spaces } => *newlines + *spaces,
         }
     }

     #[inline(always)]
     fn is_empty(&self) -> bool {
         match self {
             Repr::Heap(data) => data.is_empty(),
             Repr::Inline { len, .. } => *len as u8 == 0,
             // A substring isn't created for an empty string.
             Repr::Substring { .. } => false,
         }
     }

     #[inline]
     fn as_str(&self) -> &str {
         match self {
             Repr::Heap(data) => &*data,
             Repr::Inline { len, buf } => {
                 let len = *len as usize;
                 let buf = &buf[..len];
                 unsafe { ::core::str::from_utf8_unchecked(buf) }
             }
             Repr::Substring { newlines, spaces } => {
                 let newlines = *newlines;
                 let spaces = *spaces;
                 assert!(newlines <= N_NEWLINES && spaces <= N_SPACES);
                 &WS[N_NEWLINES - newlines..N_NEWLINES + spaces]
             }
         }
     }
 }

 #[cfg(feature = "serde")]
 mod serde {
     use alloc::{string::String, vec::Vec};
     use core::fmt;

     use serde::de::{Deserializer, Error, Unexpected, Visitor};

     use crate::SmolStr;

     // https://github.com/serde-rs/serde/blob/629802f2abfd1a54a6072992888fea7ca5bc209f/serde/src/private/de.rs#L56-L125
     fn smol_str<'de: 'a, 'a, D>(deserializer: D) -> Result<SmolStr, D::Error>
     where
         D: Deserializer<'de>,
     {
         struct SmolStrVisitor;

         impl<'a> Visitor<'a> for SmolStrVisitor {
             type Value = SmolStr;

             fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                 formatter.write_str("a string")
             }

             fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
             where
                 E: Error,
             {
                 Ok(SmolStr::from(v))
             }

             fn visit_borrowed_str<E>(self, v: &'a str) -> Result<Self::Value, E>
             where
                 E: Error,
             {
                 Ok(SmolStr::from(v))
             }

             fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
             where
                 E: Error,
             {
                 Ok(SmolStr::from(v))
             }

             fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
             where
                 E: Error,
             {
                 match core::str::from_utf8(v) {
                     Ok(s) => Ok(SmolStr::from(s)),
                     Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
                 }
             }

             fn visit_borrowed_bytes<E>(self, v: &'a [u8]) -> Result<Self::Value, E>
             where
                 E: Error,
             {
                 match core::str::from_utf8(v) {
                     Ok(s) => Ok(SmolStr::from(s)),
                     Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
                 }
             }

             fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
             where
                 E: Error,
             {
                 match String::from_utf8(v) {
                     Ok(s) => Ok(SmolStr::from(s)),
                     Err(e) => Err(Error::invalid_value(
                         Unexpected::Bytes(&e.into_bytes()),
                         &self,
                     )),
                 }
             }
         }

         deserializer.deserialize_str(SmolStrVisitor)
     }

     impl serde::Serialize for SmolStr {
         fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where
             S: serde::Serializer,
         {
             self.as_str().serialize(serializer)
         }
     }

     impl<'de> serde::Deserialize<'de> for SmolStr {
         fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
         where
             D: serde::Deserializer<'de>,
         {
             smol_str(deserializer)
         }
     }
 }
	#![no_std]
	extern crate alloc;

	use alloc::{
	borrow::Cow,
	boxed::Box,
	string::{String, ToString},
	sync::Arc,
	};
	use core::{
	borrow::Borrow,
	cmp::{self, Ordering},
	convert::Infallible,
	fmt, hash, iter,
	mem::transmute,
	ops::Deref,
	str::FromStr,
	};

	/// A `SmolStr` is a string type that has the following properties:
	///
	/// * `size_of::<SmolStr>() == 24 (therefor == size_of::<String>() on 64 bit platforms)
	/// * `Clone` is `O(1)`
	/// * Strings are stack-allocated if they are:
	/// * Up to 23 bytes long
	/// * Longer than 23 bytes, but substrings of `WS` (see below). Such strings consist
	/// solely of consecutive newlines, followed by consecutive spaces
	/// * If a string does not satisfy the aforementioned conditions, it is heap-allocated
	///
	/// Unlike `String`, however, `SmolStr` is immutable. The primary use case for
	/// `SmolStr` is a good enough default storage for tokens of typical programming
	/// languages. Strings consisting of a series of newlines, followed by a series of
	/// whitespace are a typical pattern in computer programs because of indentation.
	/// Note that a specialized interner might be a better solution for some use cases.
	///
	/// `WS`: A string of 32 newlines followed by 128 spaces.
	#[derive(Clone)]
	pub struct SmolStr(Repr);

	impl SmolStr {
	#[deprecated = "Use `new_inline` instead"]
	pub const fn new_inline_from_ascii(len: usize, bytes: &[u8]) -> SmolStr {
	let _len_is_short = [(); INLINE_CAP + 1][len];

	const ZEROS: &[u8] = &[0; INLINE_CAP];

	let mut buf = [0; INLINE_CAP];
	macro_rules! s {
	($($idx:literal),) => ( $(s!(set $idx);) );
	(set $idx:literal) => ({
	let src: &[u8] = [ZEROS, bytes][($idx < len) as usize];
	let byte = src[$idx];
	let _is_ascii = [(); 128][byte as usize];
	buf[$idx] = byte
	});
	}
	s!(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22);
	SmolStr(Repr::Inline {
	len: unsafe { transmute(len as u8) },
	buf,
	})
	}

	/// Constructs inline variant of `SmolStr`.
	///
	/// Panics if `text.len() > 23`.
	#[inline]
	pub const fn new_inline(text: &str) -> SmolStr {
	let mut buf = [0; INLINE_CAP];
	let mut i = 0;
	while i < text.len() {
	buf[i] = text.as_bytes()[i];
	i += 1
	}
	SmolStr(Repr::Inline {
	len: unsafe { transmute(text.len() as u8) },
	buf,
	})
	}

	pub fn new<T>(text: T) -> SmolStr
	where
	T: AsRef<str>,
	{
	SmolStr(Repr::new(text))
	}

	#[inline(always)]
	pub fn as_str(&self) -> &str {
	self.0.as_str()
	}

	#[inline(always)]
	pub fn to_string(&self) -> String {
	self.as_str().to_string()
	}

	#[inline(always)]
	pub fn len(&self) -> usize {
	self.0.len()
	}

	#[inline(always)]
	pub fn is_empty(&self) -> bool {
	self.0.is_empty()
	}

	#[inline(always)]
	pub fn is_heap_allocated(&self) -> bool {
	match self.0 {
	Repr::Heap(..) => true,
	_ => false,
	}
	}

	fn from_char_iter<I: iter::Iterator<Item = char>>(mut iter: I) -> SmolStr {
	let (min_size, _) = iter.size_hint();
	if min_size > INLINE_CAP {
	let heap: String = iter.collect();
	return SmolStr(Repr::Heap(heap.into_boxed_str().into()));
	}
	let mut len = 0;
	let mut buf = [0u8; INLINE_CAP];
	while let Some(ch) = iter.next() {
	let size = ch.len_utf8();
	if size + len > INLINE_CAP {
	let (min_remaining, _) = iter.size_hint();
	let mut heap = String::with_capacity(size + len + min_remaining);
	heap.push_str(core::str::from_utf8(&buf[..len]).unwrap());
	heap.push(ch);
	heap.extend(iter);
	return SmolStr(Repr::Heap(heap.into_boxed_str().into()));
	}
	ch.encode_utf8(&mut buf[len..]);
	len += size;
	}
	SmolStr(Repr::Inline {
	len: unsafe { transmute(len as u8) },
	buf,
	})
	}
	}

	impl Default for SmolStr {
	fn default() -> SmolStr {
	SmolStr::new("")
	}
	}

	impl Deref for SmolStr {
	type Target = str;

	fn deref(&self) -> &str {
	self.as_str()
	}
	}

	impl PartialEq<SmolStr> for SmolStr {
	fn eq(&self, other: &SmolStr) -> bool {
	self.as_str() == other.as_str()
	}
	}

	impl Eq for SmolStr {}

	impl PartialEq<str> for SmolStr {
	fn eq(&self, other: &str) -> bool {
	self.as_str() == other
	}
	}

	impl PartialEq<SmolStr> for str {
	fn eq(&self, other: &SmolStr) -> bool {
	other == self
	}
	}

	impl<'a> PartialEq<&'a str> for SmolStr {
	fn eq(&self, other: &&'a str) -> bool {
	self == *other
	}
	}

	impl<'a> PartialEq<SmolStr> for &'a str {
	fn eq(&self, other: &SmolStr) -> bool {
	*self == other
	}
	}

	impl PartialEq<String> for SmolStr {
	fn eq(&self, other: &String) -> bool {
	self.as_str() == other
	}
	}

	impl PartialEq<SmolStr> for String {
	fn eq(&self, other: &SmolStr) -> bool {
	other == self
	}
	}

	impl<'a> PartialEq<&'a String> for SmolStr {
	fn eq(&self, other: &&'a String) -> bool {
	self == *other
	}
	}

	impl<'a> PartialEq<SmolStr> for &'a String {
	fn eq(&self, other: &SmolStr) -> bool {
	*self == other
	}
	}

	impl Ord for SmolStr {
	fn cmp(&self, other: &SmolStr) -> Ordering {
	self.as_str().cmp(other.as_str())
	}
	}

	impl PartialOrd for SmolStr {
	fn partial_cmp(&self, other: &SmolStr) -> Option<Ordering> {
	Some(self.cmp(other))
	}
	}

	impl hash::Hash for SmolStr {
	fn hash<H: hash::Hasher>(&self, hasher: &mut H) {
	self.as_str().hash(hasher)
	}
	}

	impl fmt::Debug for SmolStr {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	fmt::Debug::fmt(self.as_str(), f)
	}
	}

	impl fmt::Display for SmolStr {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	fmt::Display::fmt(self.as_str(), f)
	}
	}

	impl iter::FromIterator<char> for SmolStr {
	fn from_iter<I: iter::IntoIterator<Item = char>>(iter: I) -> SmolStr {
	let iter = iter.into_iter();
	Self::from_char_iter(iter)
	}
	}

	fn build_from_str_iter<T>(mut iter: impl Iterator<Item = T>) -> SmolStr
	where
	T: AsRef<str>,
	String: iter::Extend<T>,
	{
	let mut len = 0;
	let mut buf = [0u8; INLINE_CAP];
	while let Some(slice) = iter.next() {
	let slice = slice.as_ref();
	let size = slice.len();
	if size + len > INLINE_CAP {
	let mut heap = String::with_capacity(size + len);
	heap.push_str(core::str::from_utf8(&buf[..len]).unwrap());
	heap.push_str(&slice);
	heap.extend(iter);
	return SmolStr(Repr::Heap(heap.into_boxed_str().into()));
	}
	(&mut buf[len..][..size]).copy_from_slice(slice.as_bytes());
	len += size;
	}
	SmolStr(Repr::Inline {
	len: unsafe { transmute(len as u8) },
	buf,
	})
	}

	impl iter::FromIterator<String> for SmolStr {
	fn from_iter<I: iter::IntoIterator<Item = String>>(iter: I) -> SmolStr {
	build_from_str_iter(iter.into_iter())
	}
	}

	impl<'a> iter::FromIterator<&'a String> for SmolStr {
	fn from_iter<I: iter::IntoIterator<Item = &'a String>>(iter: I) -> SmolStr {
	SmolStr::from_iter(iter.into_iter().map(\|x\| x.as_str()))
	}
	}

	impl<'a> iter::FromIterator<&'a str> for SmolStr {
	fn from_iter<I: iter::IntoIterator<Item = &'a str>>(iter: I) -> SmolStr {
	build_from_str_iter(iter.into_iter())
	}
	}

	impl AsRef<str> for SmolStr {
	#[inline(always)]
	fn as_ref(&self) -> &str {
	self.as_str()
	}
	}

	impl From<&str> for SmolStr {
	#[inline]
	fn from(s: &str) -> SmolStr {
	SmolStr::new(s)
	}
	}

	impl From<&mut str> for SmolStr {
	#[inline]
	fn from(s: &mut str) -> SmolStr {
	SmolStr::new(s)
	}
	}

	impl From<&String> for SmolStr {
	#[inline]
	fn from(s: &String) -> SmolStr {
	SmolStr::new(s)
	}
	}

	impl From<String> for SmolStr {
	#[inline(always)]
	fn from(text: String) -> Self {
	Self::new(text)
	}
	}

	impl From<Box<str>> for SmolStr {
	#[inline]
	fn from(s: Box<str>) -> SmolStr {
	SmolStr::new(s)
	}
	}

	impl<'a> From<Cow<'a, str>> for SmolStr {
	#[inline]
	fn from(s: Cow<'a, str>) -> SmolStr {
	SmolStr::new(s)
	}
	}

	impl From<SmolStr> for String {
	#[inline(always)]
	fn from(text: SmolStr) -> Self {
	text.as_str().into()
	}
	}

	impl Borrow<str> for SmolStr {
	#[inline(always)]
	fn borrow(&self) -> &str {
	self.as_str()
	}
	}

	impl FromStr for SmolStr {
	type Err = Infallible;

	#[inline]
	fn from_str(s: &str) -> Result<SmolStr, Self::Err> {
	Ok(SmolStr::from(s))
	}
	}

	#[cfg(feature = "arbitrary")]
	impl<'a> arbitrary::Arbitrary<'a> for SmolStr {
	fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> Result<Self, arbitrary::Error> {
	let s = <&str>::arbitrary(u)?;
	Ok(SmolStr::new(s))
	}
	}

	const INLINE_CAP: usize = 23;
	const N_NEWLINES: usize = 32;
	const N_SPACES: usize = 128;
	const WS: &str =
	"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n ";

	#[derive(Clone, Copy, Debug)]
	#[repr(u8)]
	enum InlineSize {
	_V0 = 0,
	_V1,
	_V2,
	_V3,
	_V4,
	_V5,
	_V6,
	_V7,
	_V8,
	_V9,
	_V10,
	_V11,
	_V12,
	_V13,
	_V14,
	_V15,
	_V16,
	_V17,
	_V18,
	_V19,
	_V20,
	_V21,
	_V22,
	_V23,
	}

	#[derive(Clone, Debug)]
	enum Repr {
	Heap(Arc<str>),
	Inline {
	len: InlineSize,
	buf: [u8; INLINE_CAP],
	},
	Substring {
	newlines: usize,
	spaces: usize,
	},
	}

	impl Repr {
	fn new<T>(text: T) -> Self
	where
	T: AsRef<str>,
	{
	{
	let text = text.as_ref();

	let len = text.len();
	if len <= INLINE_CAP {
	let mut buf = [0; INLINE_CAP];
	buf[..len].copy_from_slice(text.as_bytes());
	return Repr::Inline {
	len: unsafe { transmute(len as u8) },
	buf,
	};
	}

	if len <= N_NEWLINES + N_SPACES {
	let bytes = text.as_bytes();
	let possible_newline_count = cmp::min(len, N_NEWLINES);
	let newlines = bytes[..possible_newline_count]
	.iter()
	.take_while(\|&&b\| b == b'\n')
	.count();
	let possible_space_count = len - newlines;
	if possible_space_count <= N_SPACES && bytes[newlines..].iter().all(\|&b\| b == b' ')
	{
	let spaces = possible_space_count;
	return Repr::Substring { newlines, spaces };
	}
	}
	}

	Repr::Heap(text.as_ref().into())
	}

	#[inline(always)]
	fn len(&self) -> usize {
	match self {
	Repr::Heap(data) => data.len(),
	Repr::Inline { len, .. } => *len as usize,
	Repr::Substring { newlines, spaces } => newlines + spaces,
	}
	}

	#[inline(always)]
	fn is_empty(&self) -> bool {
	match self {
	Repr::Heap(data) => data.is_empty(),
	Repr::Inline { len, .. } => *len as u8 == 0,
	// A substring isn't created for an empty string.
	Repr::Substring { .. } => false,
	}
	}

	#[inline]
	fn as_str(&self) -> &str {
	match self {
	Repr::Heap(data) => &*data,
	Repr::Inline { len, buf } => {
	let len = *len as usize;
	let buf = &buf[..len];
	unsafe { ::core::str::from_utf8_unchecked(buf) }
	}
	Repr::Substring { newlines, spaces } => {
	let newlines = *newlines;
	let spaces = *spaces;
	assert!(newlines <= N_NEWLINES && spaces <= N_SPACES);
	&WS[N_NEWLINES - newlines..N_NEWLINES + spaces]
	}
	}
	}
	}

	#[cfg(feature = "serde")]
	mod serde {
	use alloc::{string::String, vec::Vec};
	use core::fmt;

	use serde::de::{Deserializer, Error, Unexpected, Visitor};

	use crate::SmolStr;

	// https://github.com/serde-rs/serde/blob/629802f2abfd1a54a6072992888fea7ca5bc209f/serde/src/private/de.rs#L56-L125
	fn smol_str<'de: 'a, 'a, D>(deserializer: D) -> Result<SmolStr, D::Error>
	where
	D: Deserializer<'de>,
	{
	struct SmolStrVisitor;

	impl<'a> Visitor<'a> for SmolStrVisitor {
	type Value = SmolStr;

	fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
	formatter.write_str("a string")
	}

	fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
	where
	E: Error,
	{
	Ok(SmolStr::from(v))
	}

	fn visit_borrowed_str<E>(self, v: &'a str) -> Result<Self::Value, E>
	where
	E: Error,
	{
	Ok(SmolStr::from(v))
	}

	fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
	where
	E: Error,
	{
	Ok(SmolStr::from(v))
	}

	fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
	where
	E: Error,
	{
	match core::str::from_utf8(v) {
	Ok(s) => Ok(SmolStr::from(s)),
	Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
	}
	}

	fn visit_borrowed_bytes<E>(self, v: &'a [u8]) -> Result<Self::Value, E>
	where
	E: Error,
	{
	match core::str::from_utf8(v) {
	Ok(s) => Ok(SmolStr::from(s)),
	Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
	}
	}

	fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
	where
	E: Error,
	{
	match String::from_utf8(v) {
	Ok(s) => Ok(SmolStr::from(s)),
	Err(e) => Err(Error::invalid_value(
	Unexpected::Bytes(&e.into_bytes()),
	&self,
	)),
	}
	}
	}

	deserializer.deserialize_str(SmolStrVisitor)
	}

	impl serde::Serialize for SmolStr {
	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
	where
	S: serde::Serializer,
	{
	self.as_str().serialize(serializer)
	}
	}

	impl<'de> serde::Deserialize<'de> for SmolStr {
	fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
	where
	D: serde::Deserializer<'de>,
	{
	smol_str(deserializer)
	}
	}
	}