src/libstd/ffi/os_str.rs - third_party/rust - Git at Google

 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.

 use borrow::{Borrow, Cow, ToOwned};
 use fmt::{self, Debug};
 use mem;
 use string::String;
 use ops;
 use cmp;
 use hash::{Hash, Hasher};
 use vec::Vec;

 use sys::os_str::{Buf, Slice};
 use sys_common::{AsInner, IntoInner, FromInner};

 /// A type that can represent owned, mutable platform-native strings, but is
 /// cheaply inter-convertible with Rust strings.
 ///
 /// The need for this type arises from the fact that:
 ///
 /// * On Unix systems, strings are often arbitrary sequences of non-zero
 ///   bytes, in many cases interpreted as UTF-8.
 ///
 /// * On Windows, strings are often arbitrary sequences of non-zero 16-bit
 ///   values, interpreted as UTF-16 when it is valid to do so.
 ///
 /// * In Rust, strings are always valid UTF-8, but may contain zeros.
 ///
 /// `OsString` and `OsStr` bridge this gap by simultaneously representing Rust
 /// and platform-native string values, and in particular allowing a Rust string
 /// to be converted into an "OS" string with no cost.
 #[derive(Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct OsString {
     inner: Buf
 }

 /// Slices into OS strings (see `OsString`).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct OsStr {
     inner: Slice
 }

 impl OsString {
     /// Constructs a new empty `OsString`.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn new() -> OsString {
         OsString { inner: Buf::from_string(String::new()) }
     }

     #[cfg(unix)]
     fn _from_bytes(vec: Vec<u8>) -> Option<OsString> {
         use os::unix::ffi::OsStringExt;
         Some(OsString::from_vec(vec))
     }

     #[cfg(windows)]
     fn _from_bytes(vec: Vec<u8>) -> Option<OsString> {
         String::from_utf8(vec).ok().map(OsString::from)
     }

     /// Converts to an `OsStr` slice.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn as_os_str(&self) -> &OsStr {
         self
     }

     /// Converts the `OsString` into a `String` if it contains valid Unicode data.
     ///
     /// On failure, ownership of the original `OsString` is returned.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn into_string(self) -> Result<String, OsString> {
         self.inner.into_string().map_err(|buf| OsString { inner: buf} )
     }

     /// Extends the string with the given `&OsStr` slice.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn push<T: AsRef<OsStr>>(&mut self, s: T) {
         self.inner.push_slice(&s.as_ref().inner)
     }

     /// Creates a new `OsString` with the given capacity.
     ///
     /// The string will be able to hold exactly `capacity` lenth units of other
     /// OS strings without reallocating. If `capacity` is 0, the string will not
     /// allocate.
     ///
     /// See main `OsString` documentation information about encoding.
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn with_capacity(capacity: usize) -> OsString {
         OsString {
             inner: Buf::with_capacity(capacity)
         }
     }

     /// Truncates the `OsString` to zero length.
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn clear(&mut self) {
         self.inner.clear()
     }

     /// Returns the capacity this `OsString` can hold without reallocating.
     ///
     /// See `OsString` introduction for information about encoding.
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn capacity(&self) -> usize {
         self.inner.capacity()
     }

     /// Reserves capacity for at least `additional` more capacity to be inserted
     /// in the given `OsString`.
     ///
     /// The collection may reserve more space to avoid frequent reallocations.
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn reserve(&mut self, additional: usize) {
         self.inner.reserve(additional)
     }

     /// Reserves the minimum capacity for exactly `additional` more capacity to
     /// be inserted in the given `OsString`. Does nothing if the capacity is
     /// already sufficient.
     ///
     /// Note that the allocator may give the collection more space than it
     /// requests. Therefore capacity can not be relied upon to be precisely
     /// minimal. Prefer reserve if future insertions are expected.
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn reserve_exact(&mut self, additional: usize) {
         self.inner.reserve_exact(additional)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl From<String> for OsString {
     fn from(s: String) -> OsString {
         OsString { inner: Buf::from_string(s) }
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T: ?Sized + AsRef<OsStr>> From<&'a T> for OsString {
     fn from(s: &'a T) -> OsString {
         s.as_ref().to_os_string()
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl ops::Index<ops::RangeFull> for OsString {
     type Output = OsStr;

     #[inline]
     fn index(&self, _index: ops::RangeFull) -> &OsStr {
         OsStr::from_inner(self.inner.as_slice())
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl ops::Deref for OsString {
     type Target = OsStr;

     #[inline]
     fn deref(&self) -> &OsStr {
         &self[..]
     }
 }

 #[stable(feature = "osstring_default", since = "1.9.0")]
 impl Default for OsString {
     #[inline]
     fn default() -> OsString {
         OsString::new()
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Debug for OsString {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         fmt::Debug::fmt(&**self, formatter)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq for OsString {
     fn eq(&self, other: &OsString) -> bool {
         &**self == &**other
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq<str> for OsString {
     fn eq(&self, other: &str) -> bool {
         &**self == other
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq<OsString> for str {
     fn eq(&self, other: &OsString) -> bool {
         &**other == self
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Eq for OsString {}

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialOrd for OsString {
     #[inline]
     fn partial_cmp(&self, other: &OsString) -> Option<cmp::Ordering> {
         (&**self).partial_cmp(&**other)
     }
     #[inline]
     fn lt(&self, other: &OsString) -> bool { &**self < &**other }
     #[inline]
     fn le(&self, other: &OsString) -> bool { &**self <= &**other }
     #[inline]
     fn gt(&self, other: &OsString) -> bool { &**self > &**other }
     #[inline]
     fn ge(&self, other: &OsString) -> bool { &**self >= &**other }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialOrd<str> for OsString {
     #[inline]
     fn partial_cmp(&self, other: &str) -> Option<cmp::Ordering> {
         (&**self).partial_cmp(other)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Ord for OsString {
     #[inline]
     fn cmp(&self, other: &OsString) -> cmp::Ordering {
         (&**self).cmp(&**other)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Hash for OsString {
     #[inline]
     fn hash<H: Hasher>(&self, state: &mut H) {
         (&**self).hash(state)
     }
 }

 impl OsStr {
     /// Coerces into an `OsStr` slice.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn new<S: AsRef<OsStr> + ?Sized>(s: &S) -> &OsStr {
         s.as_ref()
     }

     fn from_inner(inner: &Slice) -> &OsStr {
         unsafe { mem::transmute(inner) }
     }

     /// Yields a `&str` slice if the `OsStr` is valid Unicode.
     ///
     /// This conversion may entail doing a check for UTF-8 validity.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn to_str(&self) -> Option<&str> {
         self.inner.to_str()
     }

     /// Converts an `OsStr` to a `Cow<str>`.
     ///
     /// Any non-Unicode sequences are replaced with U+FFFD REPLACEMENT CHARACTER.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn to_string_lossy(&self) -> Cow<str> {
         self.inner.to_string_lossy()
     }

     /// Copies the slice into an owned `OsString`.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn to_os_string(&self) -> OsString {
         OsString { inner: self.inner.to_owned() }
     }

     /// Checks whether the `OsStr` is empty.
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn is_empty(&self) -> bool {
         self.inner.inner.is_empty()
     }

     /// Returns the length of this `OsStr`.
     ///
     /// Note that this does **not** return the number of bytes in this string
     /// as, for example, OS strings on Windows are encoded as a list of `u16`
     /// rather than a list of bytes. This number is simply useful for passing to
     /// other methods like `OsString::with_capacity` to avoid reallocations.
     ///
     /// See `OsStr` introduction for more information about encoding.
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn len(&self) -> usize {
         self.inner.inner.len()
     }

     /// Gets the underlying byte representation.
     ///
     /// Note: it is *crucial* that this API is private, to avoid
     /// revealing the internal, platform-specific encodings.
     fn bytes(&self) -> &[u8] {
         unsafe { mem::transmute(&self.inner) }
     }
 }

 #[stable(feature = "osstring_default", since = "1.9.0")]
 impl<'a> Default for &'a OsStr {
     #[inline]
     fn default() -> &'a OsStr {
         OsStr::new("")
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq for OsStr {
     fn eq(&self, other: &OsStr) -> bool {
         self.bytes().eq(other.bytes())
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq<str> for OsStr {
     fn eq(&self, other: &str) -> bool {
         *self == *OsStr::new(other)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq<OsStr> for str {
     fn eq(&self, other: &OsStr) -> bool {
         *other == *OsStr::new(self)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Eq for OsStr {}

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialOrd for OsStr {
     #[inline]
     fn partial_cmp(&self, other: &OsStr) -> Option<cmp::Ordering> {
         self.bytes().partial_cmp(other.bytes())
     }
     #[inline]
     fn lt(&self, other: &OsStr) -> bool { self.bytes().lt(other.bytes()) }
     #[inline]
     fn le(&self, other: &OsStr) -> bool { self.bytes().le(other.bytes()) }
     #[inline]
     fn gt(&self, other: &OsStr) -> bool { self.bytes().gt(other.bytes()) }
     #[inline]
     fn ge(&self, other: &OsStr) -> bool { self.bytes().ge(other.bytes()) }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialOrd<str> for OsStr {
     #[inline]
     fn partial_cmp(&self, other: &str) -> Option<cmp::Ordering> {
         self.partial_cmp(OsStr::new(other))
     }
 }

 // FIXME (#19470): cannot provide PartialOrd<OsStr> for str until we
 // have more flexible coherence rules.

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Ord for OsStr {
     #[inline]
     fn cmp(&self, other: &OsStr) -> cmp::Ordering { self.bytes().cmp(other.bytes()) }
 }

 macro_rules! impl_cmp {
     ($lhs:ty, $rhs: ty) => {
         #[stable(feature = "cmp_os_str", since = "1.8.0")]
         impl<'a, 'b> PartialEq<$rhs> for $lhs {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool { <OsStr as PartialEq>::eq(self, other) }
         }

         #[stable(feature = "cmp_os_str", since = "1.8.0")]
         impl<'a, 'b> PartialEq<$lhs> for $rhs {
             #[inline]
             fn eq(&self, other: &$lhs) -> bool { <OsStr as PartialEq>::eq(self, other) }
         }

         #[stable(feature = "cmp_os_str", since = "1.8.0")]
         impl<'a, 'b> PartialOrd<$rhs> for $lhs {
             #[inline]
             fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
                 <OsStr as PartialOrd>::partial_cmp(self, other)
             }
         }

         #[stable(feature = "cmp_os_str", since = "1.8.0")]
         impl<'a, 'b> PartialOrd<$lhs> for $rhs {
             #[inline]
             fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
                 <OsStr as PartialOrd>::partial_cmp(self, other)
             }
         }
     }
 }

 impl_cmp!(OsString, OsStr);
 impl_cmp!(OsString, &'a OsStr);
 impl_cmp!(Cow<'a, OsStr>, OsStr);
 impl_cmp!(Cow<'a, OsStr>, &'b OsStr);
 impl_cmp!(Cow<'a, OsStr>, OsString);

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Hash for OsStr {
     #[inline]
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.bytes().hash(state)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Debug for OsStr {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         self.inner.fmt(formatter)
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl Borrow<OsStr> for OsString {
     fn borrow(&self) -> &OsStr { &self[..] }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl ToOwned for OsStr {
     type Owned = OsString;
     fn to_owned(&self) -> OsString { self.to_os_string() }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for OsStr {
     fn as_ref(&self) -> &OsStr {
         self
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for OsString {
     fn as_ref(&self) -> &OsStr {
         self
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for str {
     fn as_ref(&self) -> &OsStr {
         OsStr::from_inner(Slice::from_str(self))
     }
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRef<OsStr> for String {
     fn as_ref(&self) -> &OsStr {
         (&**self).as_ref()
     }
 }

 impl FromInner<Buf> for OsString {
     fn from_inner(buf: Buf) -> OsString {
         OsString { inner: buf }
     }
 }

 impl IntoInner<Buf> for OsString {
     fn into_inner(self) -> Buf {
         self.inner
     }
 }

 impl AsInner<Slice> for OsStr {
     fn as_inner(&self) -> &Slice {
         &self.inner
     }
 }

 #[cfg(test)]
 mod tests {
     use super::*;
     use sys_common::{AsInner, IntoInner};

     #[test]
     fn test_os_string_with_capacity() {
         let os_string = OsString::with_capacity(0);
         assert_eq!(0, os_string.inner.into_inner().capacity());

         let os_string = OsString::with_capacity(10);
         assert_eq!(10, os_string.inner.into_inner().capacity());

         let mut os_string = OsString::with_capacity(0);
         os_string.push("abc");
         assert!(os_string.inner.into_inner().capacity() >= 3);
     }

     #[test]
     fn test_os_string_clear() {
         let mut os_string = OsString::from("abc");
         assert_eq!(3, os_string.inner.as_inner().len());

         os_string.clear();
         assert_eq!(&os_string, "");
         assert_eq!(0, os_string.inner.as_inner().len());
     }

     #[test]
     fn test_os_string_capacity() {
         let os_string = OsString::with_capacity(0);
         assert_eq!(0, os_string.capacity());

         let os_string = OsString::with_capacity(10);
         assert_eq!(10, os_string.capacity());

         let mut os_string = OsString::with_capacity(0);
         os_string.push("abc");
         assert!(os_string.capacity() >= 3);
     }

     #[test]
     fn test_os_string_reserve() {
         let mut os_string = OsString::new();
         assert_eq!(os_string.capacity(), 0);

         os_string.reserve(2);
         assert!(os_string.capacity() >= 2);

         for _ in 0..16 {
             os_string.push("a");
         }

         assert!(os_string.capacity() >= 16);
         os_string.reserve(16);
         assert!(os_string.capacity() >= 32);

         os_string.push("a");

         os_string.reserve(16);
         assert!(os_string.capacity() >= 33)
     }

     #[test]
     fn test_os_string_reserve_exact() {
         let mut os_string = OsString::new();
         assert_eq!(os_string.capacity(), 0);

         os_string.reserve_exact(2);
         assert!(os_string.capacity() >= 2);

         for _ in 0..16 {
             os_string.push("a");
         }

         assert!(os_string.capacity() >= 16);
         os_string.reserve_exact(16);
         assert!(os_string.capacity() >= 32);

         os_string.push("a");

         os_string.reserve_exact(16);
         assert!(os_string.capacity() >= 33)
     }

     #[test]
     fn test_os_string_default() {
         let os_string: OsString = Default::default();
         assert_eq!("", &os_string);
     }

     #[test]
     fn test_os_str_is_empty() {
         let mut os_string = OsString::new();
         assert!(os_string.is_empty());

         os_string.push("abc");
         assert!(!os_string.is_empty());

         os_string.clear();
         assert!(os_string.is_empty());
     }

     #[test]
     fn test_os_str_len() {
         let mut os_string = OsString::new();
         assert_eq!(0, os_string.len());

         os_string.push("abc");
         assert_eq!(3, os_string.len());

         os_string.clear();
         assert_eq!(0, os_string.len());
     }

     #[test]
     fn test_os_str_default() {
         let os_str: &OsStr = Default::default();
         assert_eq!("", os_str);
     }
 }
	// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
	// file at the top-level directory of this distribution and at
	// http://rust-lang.org/COPYRIGHT.
	//
	// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
	// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
	// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
	// option. This file may not be copied, modified, or distributed
	// except according to those terms.

	use borrow::{Borrow, Cow, ToOwned};
	use fmt::{self, Debug};
	use mem;
	use string::String;
	use ops;
	use cmp;
	use hash::{Hash, Hasher};
	use vec::Vec;

	use sys::os_str::{Buf, Slice};
	use sys_common::{AsInner, IntoInner, FromInner};

	/// A type that can represent owned, mutable platform-native strings, but is
	/// cheaply inter-convertible with Rust strings.
	///
	/// The need for this type arises from the fact that:
	///
	/// * On Unix systems, strings are often arbitrary sequences of non-zero
	/// bytes, in many cases interpreted as UTF-8.
	///
	/// * On Windows, strings are often arbitrary sequences of non-zero 16-bit
	/// values, interpreted as UTF-16 when it is valid to do so.
	///
	/// * In Rust, strings are always valid UTF-8, but may contain zeros.
	///
	/// `OsString` and `OsStr` bridge this gap by simultaneously representing Rust
	/// and platform-native string values, and in particular allowing a Rust string
	/// to be converted into an "OS" string with no cost.
	#[derive(Clone)]
	#[stable(feature = "rust1", since = "1.0.0")]
	pub struct OsString {
	inner: Buf
	}

	/// Slices into OS strings (see `OsString`).
	#[stable(feature = "rust1", since = "1.0.0")]
	pub struct OsStr {
	inner: Slice
	}

	impl OsString {
	/// Constructs a new empty `OsString`.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn new() -> OsString {
	OsString { inner: Buf::from_string(String::new()) }
	}

	#[cfg(unix)]
	fn _from_bytes(vec: Vec<u8>) -> Option<OsString> {
	use os::unix::ffi::OsStringExt;
	Some(OsString::from_vec(vec))
	}

	#[cfg(windows)]
	fn _from_bytes(vec: Vec<u8>) -> Option<OsString> {
	String::from_utf8(vec).ok().map(OsString::from)
	}

	/// Converts to an `OsStr` slice.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn as_os_str(&self) -> &OsStr {
	self
	}

	/// Converts the `OsString` into a `String` if it contains valid Unicode data.
	///
	/// On failure, ownership of the original `OsString` is returned.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn into_string(self) -> Result<String, OsString> {
	self.inner.into_string().map_err(\|buf\| OsString { inner: buf} )
	}

	/// Extends the string with the given `&OsStr` slice.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn push<T: AsRef<OsStr>>(&mut self, s: T) {
	self.inner.push_slice(&s.as_ref().inner)
	}

	/// Creates a new `OsString` with the given capacity.
	///
	/// The string will be able to hold exactly `capacity` lenth units of other
	/// OS strings without reallocating. If `capacity` is 0, the string will not
	/// allocate.
	///
	/// See main `OsString` documentation information about encoding.
	#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
	pub fn with_capacity(capacity: usize) -> OsString {
	OsString {
	inner: Buf::with_capacity(capacity)
	}
	}

	/// Truncates the `OsString` to zero length.
	#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
	pub fn clear(&mut self) {
	self.inner.clear()
	}

	/// Returns the capacity this `OsString` can hold without reallocating.
	///
	/// See `OsString` introduction for information about encoding.
	#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
	pub fn capacity(&self) -> usize {
	self.inner.capacity()
	}

	/// Reserves capacity for at least `additional` more capacity to be inserted
	/// in the given `OsString`.
	///
	/// The collection may reserve more space to avoid frequent reallocations.
	#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
	pub fn reserve(&mut self, additional: usize) {
	self.inner.reserve(additional)
	}

	/// Reserves the minimum capacity for exactly `additional` more capacity to
	/// be inserted in the given `OsString`. Does nothing if the capacity is
	/// already sufficient.
	///
	/// Note that the allocator may give the collection more space than it
	/// requests. Therefore capacity can not be relied upon to be precisely
	/// minimal. Prefer reserve if future insertions are expected.
	#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
	pub fn reserve_exact(&mut self, additional: usize) {
	self.inner.reserve_exact(additional)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl From<String> for OsString {
	fn from(s: String) -> OsString {
	OsString { inner: Buf::from_string(s) }
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl<'a, T: ?Sized + AsRef<OsStr>> From<&'a T> for OsString {
	fn from(s: &'a T) -> OsString {
	s.as_ref().to_os_string()
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl ops::Index<ops::RangeFull> for OsString {
	type Output = OsStr;

	#[inline]
	fn index(&self, _index: ops::RangeFull) -> &OsStr {
	OsStr::from_inner(self.inner.as_slice())
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl ops::Deref for OsString {
	type Target = OsStr;

	#[inline]
	fn deref(&self) -> &OsStr {
	&self[..]
	}
	}

	#[stable(feature = "osstring_default", since = "1.9.0")]
	impl Default for OsString {
	#[inline]
	fn default() -> OsString {
	OsString::new()
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Debug for OsString {
	fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
	fmt::Debug::fmt(&**self, formatter)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialEq for OsString {
	fn eq(&self, other: &OsString) -> bool {
	&self == &other
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialEq<str> for OsString {
	fn eq(&self, other: &str) -> bool {
	&**self == other
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialEq<OsString> for str {
	fn eq(&self, other: &OsString) -> bool {
	&**other == self
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Eq for OsString {}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialOrd for OsString {
	#[inline]
	fn partial_cmp(&self, other: &OsString) -> Option<cmp::Ordering> {
	(&self).partial_cmp(&other)
	}
	#[inline]
	fn lt(&self, other: &OsString) -> bool { &self < &other }
	#[inline]
	fn le(&self, other: &OsString) -> bool { &self <= &other }
	#[inline]
	fn gt(&self, other: &OsString) -> bool { &self > &other }
	#[inline]
	fn ge(&self, other: &OsString) -> bool { &self >= &other }
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialOrd<str> for OsString {
	#[inline]
	fn partial_cmp(&self, other: &str) -> Option<cmp::Ordering> {
	(&**self).partial_cmp(other)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Ord for OsString {
	#[inline]
	fn cmp(&self, other: &OsString) -> cmp::Ordering {
	(&self).cmp(&other)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Hash for OsString {
	#[inline]
	fn hash<H: Hasher>(&self, state: &mut H) {
	(&**self).hash(state)
	}
	}

	impl OsStr {
	/// Coerces into an `OsStr` slice.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn new<S: AsRef<OsStr> + ?Sized>(s: &S) -> &OsStr {
	s.as_ref()
	}

	fn from_inner(inner: &Slice) -> &OsStr {
	unsafe { mem::transmute(inner) }
	}

	/// Yields a `&str` slice if the `OsStr` is valid Unicode.
	///
	/// This conversion may entail doing a check for UTF-8 validity.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn to_str(&self) -> Option<&str> {
	self.inner.to_str()
	}

	/// Converts an `OsStr` to a `Cow<str>`.
	///
	/// Any non-Unicode sequences are replaced with U+FFFD REPLACEMENT CHARACTER.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn to_string_lossy(&self) -> Cow<str> {
	self.inner.to_string_lossy()
	}

	/// Copies the slice into an owned `OsString`.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub fn to_os_string(&self) -> OsString {
	OsString { inner: self.inner.to_owned() }
	}

	/// Checks whether the `OsStr` is empty.
	#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
	pub fn is_empty(&self) -> bool {
	self.inner.inner.is_empty()
	}

	/// Returns the length of this `OsStr`.
	///
	/// Note that this does not return the number of bytes in this string
	/// as, for example, OS strings on Windows are encoded as a list of `u16`
	/// rather than a list of bytes. This number is simply useful for passing to
	/// other methods like `OsString::with_capacity` to avoid reallocations.
	///
	/// See `OsStr` introduction for more information about encoding.
	#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
	pub fn len(&self) -> usize {
	self.inner.inner.len()
	}

	/// Gets the underlying byte representation.
	///
	/// Note: it is crucial that this API is private, to avoid
	/// revealing the internal, platform-specific encodings.
	fn bytes(&self) -> &[u8] {
	unsafe { mem::transmute(&self.inner) }
	}
	}

	#[stable(feature = "osstring_default", since = "1.9.0")]
	impl<'a> Default for &'a OsStr {
	#[inline]
	fn default() -> &'a OsStr {
	OsStr::new("")
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialEq for OsStr {
	fn eq(&self, other: &OsStr) -> bool {
	self.bytes().eq(other.bytes())
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialEq<str> for OsStr {
	fn eq(&self, other: &str) -> bool {
	self == OsStr::new(other)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialEq<OsStr> for str {
	fn eq(&self, other: &OsStr) -> bool {
	other == OsStr::new(self)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Eq for OsStr {}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialOrd for OsStr {
	#[inline]
	fn partial_cmp(&self, other: &OsStr) -> Option<cmp::Ordering> {
	self.bytes().partial_cmp(other.bytes())
	}
	#[inline]
	fn lt(&self, other: &OsStr) -> bool { self.bytes().lt(other.bytes()) }
	#[inline]
	fn le(&self, other: &OsStr) -> bool { self.bytes().le(other.bytes()) }
	#[inline]
	fn gt(&self, other: &OsStr) -> bool { self.bytes().gt(other.bytes()) }
	#[inline]
	fn ge(&self, other: &OsStr) -> bool { self.bytes().ge(other.bytes()) }
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl PartialOrd<str> for OsStr {
	#[inline]
	fn partial_cmp(&self, other: &str) -> Option<cmp::Ordering> {
	self.partial_cmp(OsStr::new(other))
	}
	}

	// FIXME (#19470): cannot provide PartialOrd<OsStr> for str until we
	// have more flexible coherence rules.

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Ord for OsStr {
	#[inline]
	fn cmp(&self, other: &OsStr) -> cmp::Ordering { self.bytes().cmp(other.bytes()) }
	}

	macro_rules! impl_cmp {
	($lhs:ty, $rhs: ty) => {
	#[stable(feature = "cmp_os_str", since = "1.8.0")]
	impl<'a, 'b> PartialEq<$rhs> for $lhs {
	#[inline]
	fn eq(&self, other: &$rhs) -> bool { <OsStr as PartialEq>::eq(self, other) }
	}

	#[stable(feature = "cmp_os_str", since = "1.8.0")]
	impl<'a, 'b> PartialEq<$lhs> for $rhs {
	#[inline]
	fn eq(&self, other: &$lhs) -> bool { <OsStr as PartialEq>::eq(self, other) }
	}

	#[stable(feature = "cmp_os_str", since = "1.8.0")]
	impl<'a, 'b> PartialOrd<$rhs> for $lhs {
	#[inline]
	fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
	<OsStr as PartialOrd>::partial_cmp(self, other)
	}
	}

	#[stable(feature = "cmp_os_str", since = "1.8.0")]
	impl<'a, 'b> PartialOrd<$lhs> for $rhs {
	#[inline]
	fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
	<OsStr as PartialOrd>::partial_cmp(self, other)
	}
	}
	}
	}

	impl_cmp!(OsString, OsStr);
	impl_cmp!(OsString, &'a OsStr);
	impl_cmp!(Cow<'a, OsStr>, OsStr);
	impl_cmp!(Cow<'a, OsStr>, &'b OsStr);
	impl_cmp!(Cow<'a, OsStr>, OsString);

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Hash for OsStr {
	#[inline]
	fn hash<H: Hasher>(&self, state: &mut H) {
	self.bytes().hash(state)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Debug for OsStr {
	fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
	self.inner.fmt(formatter)
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl Borrow<OsStr> for OsString {
	fn borrow(&self) -> &OsStr { &self[..] }
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl ToOwned for OsStr {
	type Owned = OsString;
	fn to_owned(&self) -> OsString { self.to_os_string() }
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl AsRef<OsStr> for OsStr {
	fn as_ref(&self) -> &OsStr {
	self
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl AsRef<OsStr> for OsString {
	fn as_ref(&self) -> &OsStr {
	self
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl AsRef<OsStr> for str {
	fn as_ref(&self) -> &OsStr {
	OsStr::from_inner(Slice::from_str(self))
	}
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl AsRef<OsStr> for String {
	fn as_ref(&self) -> &OsStr {
	(&**self).as_ref()
	}
	}

	impl FromInner<Buf> for OsString {
	fn from_inner(buf: Buf) -> OsString {
	OsString { inner: buf }
	}
	}

	impl IntoInner<Buf> for OsString {
	fn into_inner(self) -> Buf {
	self.inner
	}
	}

	impl AsInner<Slice> for OsStr {
	fn as_inner(&self) -> &Slice {
	&self.inner
	}
	}

	#[cfg(test)]
	mod tests {
	use super::*;
	use sys_common::{AsInner, IntoInner};

	#[test]
	fn test_os_string_with_capacity() {
	let os_string = OsString::with_capacity(0);
	assert_eq!(0, os_string.inner.into_inner().capacity());

	let os_string = OsString::with_capacity(10);
	assert_eq!(10, os_string.inner.into_inner().capacity());

	let mut os_string = OsString::with_capacity(0);
	os_string.push("abc");
	assert!(os_string.inner.into_inner().capacity() >= 3);
	}

	#[test]
	fn test_os_string_clear() {
	let mut os_string = OsString::from("abc");
	assert_eq!(3, os_string.inner.as_inner().len());

	os_string.clear();
	assert_eq!(&os_string, "");
	assert_eq!(0, os_string.inner.as_inner().len());
	}

	#[test]
	fn test_os_string_capacity() {
	let os_string = OsString::with_capacity(0);
	assert_eq!(0, os_string.capacity());

	let os_string = OsString::with_capacity(10);
	assert_eq!(10, os_string.capacity());

	let mut os_string = OsString::with_capacity(0);
	os_string.push("abc");
	assert!(os_string.capacity() >= 3);
	}

	#[test]
	fn test_os_string_reserve() {
	let mut os_string = OsString::new();
	assert_eq!(os_string.capacity(), 0);

	os_string.reserve(2);
	assert!(os_string.capacity() >= 2);

	for _ in 0..16 {
	os_string.push("a");
	}

	assert!(os_string.capacity() >= 16);
	os_string.reserve(16);
	assert!(os_string.capacity() >= 32);

	os_string.push("a");

	os_string.reserve(16);
	assert!(os_string.capacity() >= 33)
	}

	#[test]
	fn test_os_string_reserve_exact() {
	let mut os_string = OsString::new();
	assert_eq!(os_string.capacity(), 0);

	os_string.reserve_exact(2);
	assert!(os_string.capacity() >= 2);

	for _ in 0..16 {
	os_string.push("a");
	}

	assert!(os_string.capacity() >= 16);
	os_string.reserve_exact(16);
	assert!(os_string.capacity() >= 32);

	os_string.push("a");

	os_string.reserve_exact(16);
	assert!(os_string.capacity() >= 33)
	}

	#[test]
	fn test_os_string_default() {
	let os_string: OsString = Default::default();
	assert_eq!("", &os_string);
	}

	#[test]
	fn test_os_str_is_empty() {
	let mut os_string = OsString::new();
	assert!(os_string.is_empty());

	os_string.push("abc");
	assert!(!os_string.is_empty());

	os_string.clear();
	assert!(os_string.is_empty());
	}

	#[test]
	fn test_os_str_len() {
	let mut os_string = OsString::new();
	assert_eq!(0, os_string.len());

	os_string.push("abc");
	assert_eq!(3, os_string.len());

	os_string.clear();
	assert_eq!(0, os_string.len());
	}

	#[test]
	fn test_os_str_default() {
	let os_str: &OsStr = Default::default();
	assert_eq!("", os_str);
	}
	}