diff options
Diffstat (limited to 'src/libstd/ffi/c_str.rs')
| -rw-r--r-- | src/libstd/ffi/c_str.rs | 331 |
1 files changed, 255 insertions, 76 deletions
diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs index 7992aefcb42..a2022a2eeb2 100644 --- a/src/libstd/ffi/c_str.rs +++ b/src/libstd/ffi/c_str.rs @@ -14,28 +14,80 @@ use cmp::Ordering; use error::Error; use fmt::{self, Write}; use io; -use libc; use mem; use memchr; use ops; use os::raw::c_char; use ptr; +use rc::Rc; use slice; use str::{self, Utf8Error}; +use sync::Arc; +use sys; -/// A type representing an owned C-compatible string. +/// A type representing an owned, C-compatible, nul-terminated string with no nul bytes in the +/// middle. /// -/// This type serves the primary purpose of being able to safely generate a +/// This type serves the purpose of being able to safely generate a /// C-compatible string from a Rust byte slice or vector. An instance of this /// type is a static guarantee that the underlying bytes contain no interior 0 -/// bytes and the final byte is 0. +/// bytes ("nul characters") and that the final byte is 0 ("nul terminator"). /// -/// A `CString` is created from either a byte slice or a byte vector. A [`u8`] -/// slice can be obtained with the `as_bytes` method. Slices produced from a -/// `CString` do *not* contain the trailing nul terminator unless otherwise -/// specified. +/// `CString` is to [`CStr`] as [`String`] is to [`&str`]: the former +/// in each pair are owned strings; the latter are borrowed +/// references. /// +/// # Creating a `CString` +/// +/// A `CString` is created from either a byte slice or a byte vector, +/// or anything that implements [`Into`]`<`[`Vec`]`<`[`u8`]`>>` (for +/// example, you can build a `CString` straight out of a [`String`] or +/// a [`&str`], since both implement that trait). +/// +/// The [`new`] method will actually check that the provided `&[u8]` +/// does not have 0 bytes in the middle, and return an error if it +/// finds one. +/// +/// # Extracting a raw pointer to the whole C string +/// +/// `CString` implements a [`as_ptr`] method through the [`Deref`] +/// trait. This method will give you a `*const c_char` which you can +/// feed directly to extern functions that expect a nul-terminated +/// string, like C's `strdup()`. +/// +/// # Extracting a slice of the whole C string +/// +/// Alternatively, you can obtain a `&[`[`u8`]`]` slice from a +/// `CString` with the [`as_bytes`] method. Slices produced in this +/// way do *not* contain the trailing nul terminator. This is useful +/// when you will be calling an extern function that takes a `*const +/// u8` argument which is not necessarily nul-terminated, plus another +/// argument with the length of the string — like C's `strndup()`. +/// You can of course get the slice's length with its +/// [`len`][slice.len] method. +/// +/// If you need a `&[`[`u8`]`]` slice *with* the nul terminator, you +/// can use [`as_bytes_with_nul`] instead. +/// +/// Once you have the kind of slice you need (with or without a nul +/// terminator), you can call the slice's own +/// [`as_ptr`][slice.as_ptr] method to get a raw pointer to pass to +/// extern functions. See the documentation for that function for a +/// discussion on ensuring the lifetime of the raw pointer. +/// +/// [`Into`]: ../convert/trait.Into.html +/// [`Vec`]: ../vec/struct.Vec.html +/// [`String`]: ../string/struct.String.html +/// [`&str`]: ../primitive.str.html /// [`u8`]: ../primitive.u8.html +/// [`new`]: #method.new +/// [`as_bytes`]: #method.as_bytes +/// [`as_bytes_with_nul`]: #method.as_bytes_with_nul +/// [`as_ptr`]: #method.as_ptr +/// [slice.as_ptr]: ../primitive.slice.html#method.as_ptr +/// [slice.len]: ../primitive.slice.html#method.len +/// [`Deref`]: ../ops/trait.Deref.html +/// [`CStr`]: struct.CStr.html /// /// # Examples /// @@ -48,6 +100,8 @@ use str::{self, Utf8Error}; /// fn my_printer(s: *const c_char); /// } /// +/// // We are certain that our string doesn't have 0 bytes in the middle, +/// // so we can .unwrap() /// let c_to_print = CString::new("Hello, world!").unwrap(); /// unsafe { /// my_printer(c_to_print.as_ptr()); @@ -58,7 +112,7 @@ use str::{self, Utf8Error}; /// # Safety /// /// `CString` is intended for working with traditional C-style strings -/// (a sequence of non-null bytes terminated by a single null byte); the +/// (a sequence of non-nul bytes terminated by a single nul byte); the /// primary use case for these kinds of strings is interoperating with C-like /// code. Often you will need to transfer ownership to/from that external /// code. It is strongly recommended that you thoroughly read through the @@ -77,17 +131,21 @@ pub struct CString { /// Representation of a borrowed C string. /// -/// This dynamically sized type is only safely constructed via a borrowed -/// version of an instance of `CString`. This type can be constructed from a raw -/// C string as well and represents a C string borrowed from another location. +/// This type represents a borrowed reference to a nul-terminated +/// array of bytes. It can be constructed safely from a `&[`[`u8`]`]` +/// slice, or unsafely from a raw `*const c_char`. It can then be +/// converted to a Rust [`&str`] by performing UTF-8 validation, or +/// into an owned [`CString`]. +/// +/// `CStr` is to [`CString`] as [`&str`] is to [`String`]: the former +/// in each pair are borrowed references; the latter are owned +/// strings. /// /// Note that this structure is **not** `repr(C)` and is not recommended to be -/// placed in the signatures of FFI functions. Instead safe wrappers of FFI +/// placed in the signatures of FFI functions. Instead, safe wrappers of FFI /// functions may leverage the unsafe [`from_ptr`] constructor to provide a safe /// interface to other consumers. /// -/// [`from_ptr`]: #method.from_ptr -/// /// # Examples /// /// Inspecting a foreign C string: @@ -100,7 +158,7 @@ pub struct CString { /// /// unsafe { /// let slice = CStr::from_ptr(my_string()); -/// println!("string length: {}", slice.to_bytes().len()); +/// println!("string buffer size without nul terminator: {}", slice.to_bytes().len()); /// } /// ``` /// @@ -122,8 +180,6 @@ pub struct CString { /// /// Converting a foreign C string into a Rust [`String`]: /// -/// [`String`]: ../string/struct.String.html -/// /// ```no_run /// use std::ffi::CStr; /// use std::os::raw::c_char; @@ -138,6 +194,12 @@ pub struct CString { /// /// println!("string: {}", my_string_safe()); /// ``` +/// +/// [`u8`]: ../primitive.u8.html +/// [`&str`]: ../primitive.str.html +/// [`String`]: ../string/struct.String.html +/// [`CString`]: struct.CString.html +/// [`from_ptr`]: #method.from_ptr #[derive(Hash)] #[stable(feature = "rust1", since = "1.0.0")] pub struct CStr { @@ -148,9 +210,15 @@ pub struct CStr { inner: [c_char] } -/// An error returned from [`CString::new`] to indicate that a nul byte was found -/// in the vector provided. +/// An error indicating that an interior nul byte was found. +/// +/// While Rust strings may contain nul bytes in the middle, C strings +/// can't, as that byte would effectively truncate the string. /// +/// This error is created by the [`new`][`CString::new`] method on +/// [`CString`]. See its documentation for more. +/// +/// [`CString`]: struct.CString.html /// [`CString::new`]: struct.CString.html#method.new /// /// # Examples @@ -164,9 +232,16 @@ pub struct CStr { #[stable(feature = "rust1", since = "1.0.0")] pub struct NulError(usize, Vec<u8>); -/// An error returned from [`CStr::from_bytes_with_nul`] to indicate that a nul -/// byte was found too early in the slice provided or one wasn't found at all. +/// An error indicating that a nul byte was not in the expected position. +/// +/// The slice used to create a [`CStr`] must have one and only one nul +/// byte at the end of the slice. /// +/// This error is created by the +/// [`from_bytes_with_nul`][`CStr::from_bytes_with_nul`] method on +/// [`CStr`]. See its documentation for more. +/// +/// [`CStr`]: struct.CStr.html /// [`CStr::from_bytes_with_nul`]: struct.CStr.html#method.from_bytes_with_nul /// /// # Examples @@ -201,9 +276,18 @@ impl FromBytesWithNulError { } } -/// An error returned from [`CString::into_string`] to indicate that a UTF-8 error -/// was encountered during the conversion. +/// An error indicating invalid UTF-8 when converting a [`CString`] into a [`String`]. +/// +/// `CString` is just a wrapper over a buffer of bytes with a nul +/// terminator; [`into_string`][`CString::into_string`] performs UTF-8 +/// validation on those bytes and may return this error. /// +/// This `struct` is created by the +/// [`into_string`][`CString::into_string`] method on [`CString`]. See +/// its documentation for more. +/// +/// [`String`]: ../string/struct.String.html +/// [`CString`]: struct.CString.html /// [`CString::into_string`]: struct.CString.html#method.into_string #[derive(Clone, PartialEq, Eq, Debug)] #[stable(feature = "cstring_into", since = "1.7.0")] @@ -215,8 +299,11 @@ pub struct IntoStringError { impl CString { /// Creates a new C-compatible string from a container of bytes. /// - /// This method will consume the provided data and use the underlying bytes - /// to construct a new string, ensuring that there is a trailing 0 byte. + /// This function will consume the provided data and use the + /// underlying bytes to construct a new string, ensuring that + /// there is a trailing 0 byte. This trailing 0 byte will be + /// appended by this function; the provided data should *not* + /// contain any 0 bytes in it. /// /// # Examples /// @@ -234,9 +321,11 @@ impl CString { /// /// # Errors /// - /// This function will return an error if the bytes yielded contain an - /// internal 0 byte. The error returned will contain the bytes as well as + /// This function will return an error if the supplied bytes contain an + /// internal 0 byte. The [`NulError`] returned will contain the bytes as well as /// the position of the nul byte. + /// + /// [`NulError`]: struct.NulError.html #[stable(feature = "rust1", since = "1.0.0")] pub fn new<T: Into<Vec<u8>>>(t: T) -> Result<CString, NulError> { Self::_new(t.into()) @@ -249,8 +338,8 @@ impl CString { } } - /// Creates a C-compatible string from a byte vector without checking for - /// interior 0 bytes. + /// Creates a C-compatible string by consuming a byte vector, + /// without checking for interior 0 bytes. /// /// This method is equivalent to [`new`] except that no runtime assertion /// is made that `v` contains no 0 bytes, and it requires an actual @@ -275,7 +364,7 @@ impl CString { CString { inner: v.into_boxed_slice() } } - /// Retakes ownership of a `CString` that was transferred to C. + /// Retakes ownership of a `CString` that was transferred to C via [`into_raw`]. /// /// Additionally, the length of the string will be recalculated from the pointer. /// @@ -286,7 +375,14 @@ impl CString { /// ownership of a string that was allocated by foreign code) is likely to lead /// to undefined behavior or allocator corruption. /// + /// > **Note:** If you need to borrow a string that was allocated by + /// > foreign code, use [`CStr`]. If you need to take ownership of + /// > a string that was allocated by foreign code, you will need to + /// > make your own provisions for freeing it appropriately, likely + /// > with the foreign code's API to do that. + /// /// [`into_raw`]: #method.into_raw + /// [`CStr`]: struct.CStr.html /// /// # Examples /// @@ -310,16 +406,16 @@ impl CString { /// ``` #[stable(feature = "cstr_memory", since = "1.4.0")] pub unsafe fn from_raw(ptr: *mut c_char) -> CString { - let len = libc::strlen(ptr) + 1; // Including the NUL byte - let slice = slice::from_raw_parts(ptr, len as usize); - CString { inner: mem::transmute(slice) } + let len = sys::strlen(ptr) + 1; // Including the NUL byte + let slice = slice::from_raw_parts_mut(ptr, len as usize); + CString { inner: Box::from_raw(slice as *mut [c_char] as *mut [u8]) } } - /// Transfers ownership of the string to a C caller. + /// Consumes the `CString` and transfers ownership of the string to a C caller. /// - /// The pointer must be returned to Rust and reconstituted using + /// The pointer which this function returns must be returned to Rust and reconstituted using /// [`from_raw`] to be properly deallocated. Specifically, one - /// should *not* use the standard C `free` function to deallocate + /// should *not* use the standard C `free()` function to deallocate /// this string. /// /// Failure to call [`from_raw`] will lead to a memory leak. @@ -351,11 +447,27 @@ impl CString { Box::into_raw(self.into_inner()) as *mut c_char } - /// Converts the `CString` into a [`String`] if it contains valid Unicode data. + /// Converts the `CString` into a [`String`] if it contains valid UTF-8 data. /// /// On failure, ownership of the original `CString` is returned. /// /// [`String`]: ../string/struct.String.html + /// + /// # Examples + /// + /// ``` + /// use std::ffi::CString; + /// + /// let valid_utf8 = vec![b'f', b'o', b'o']; + /// let cstring = CString::new(valid_utf8).unwrap(); + /// assert_eq!(cstring.into_string().unwrap(), "foo"); + /// + /// let invalid_utf8 = vec![b'f', 0xff, b'o', b'o']; + /// let cstring = CString::new(invalid_utf8).unwrap(); + /// let err = cstring.into_string().err().unwrap(); + /// assert_eq!(err.utf8_error().valid_up_to(), 1); + /// ``` + #[stable(feature = "cstring_into", since = "1.7.0")] pub fn into_string(self) -> Result<String, IntoStringError> { String::from_utf8(self.into_bytes()) @@ -365,10 +477,11 @@ impl CString { }) } - /// Returns the underlying byte buffer. + /// Consumes the `CString` and returns the underlying byte buffer. /// - /// The returned buffer does **not** contain the trailing nul separator and - /// it is guaranteed to not have any interior nul bytes. + /// The returned buffer does **not** contain the trailing nul + /// terminator, and it is guaranteed to not have any interior nul + /// bytes. /// /// # Examples /// @@ -388,7 +501,7 @@ impl CString { } /// Equivalent to the [`into_bytes`] function except that the returned vector - /// includes the trailing nul byte. + /// includes the trailing nul terminator. /// /// [`into_bytes`]: #method.into_bytes /// @@ -408,8 +521,12 @@ impl CString { /// Returns the contents of this `CString` as a slice of bytes. /// - /// The returned slice does **not** contain the trailing nul separator and - /// it is guaranteed to not have any interior nul bytes. + /// The returned slice does **not** contain the trailing nul + /// terminator, and it is guaranteed to not have any interior nul + /// bytes. If you need the nul terminator, use + /// [`as_bytes_with_nul`] instead. + /// + /// [`as_bytes_with_nul`]: #method.as_bytes_with_nul /// /// # Examples /// @@ -427,7 +544,7 @@ impl CString { } /// Equivalent to the [`as_bytes`] function except that the returned slice - /// includes the trailing nul byte. + /// includes the trailing nul terminator. /// /// [`as_bytes`]: #method.as_bytes /// @@ -480,7 +597,7 @@ impl CString { /// ``` #[stable(feature = "into_boxed_c_str", since = "1.20.0")] pub fn into_boxed_c_str(self) -> Box<CStr> { - unsafe { mem::transmute(self.into_inner()) } + unsafe { Box::from_raw(Box::into_raw(self.into_inner()) as *mut CStr) } } // Bypass "move out of struct which implements [`Drop`] trait" restriction. @@ -569,7 +686,7 @@ impl Borrow<CStr> for CString { impl<'a> From<&'a CStr> for Box<CStr> { fn from(s: &'a CStr) -> Box<CStr> { let boxed: Box<[u8]> = Box::from(s.to_bytes_with_nul()); - unsafe { mem::transmute(boxed) } + unsafe { Box::from_raw(Box::into_raw(boxed) as *mut CStr) } } } @@ -589,17 +706,53 @@ impl From<CString> for Box<CStr> { } } +#[stable(feature = "shared_from_slice2", since = "1.23.0")] +impl From<CString> for Arc<CStr> { + #[inline] + fn from(s: CString) -> Arc<CStr> { + let arc: Arc<[u8]> = Arc::from(s.into_inner()); + unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) } + } +} + +#[stable(feature = "shared_from_slice2", since = "1.23.0")] +impl<'a> From<&'a CStr> for Arc<CStr> { + #[inline] + fn from(s: &CStr) -> Arc<CStr> { + let arc: Arc<[u8]> = Arc::from(s.to_bytes_with_nul()); + unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) } + } +} + +#[stable(feature = "shared_from_slice2", since = "1.23.0")] +impl From<CString> for Rc<CStr> { + #[inline] + fn from(s: CString) -> Rc<CStr> { + let rc: Rc<[u8]> = Rc::from(s.into_inner()); + unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) } + } +} + +#[stable(feature = "shared_from_slice2", since = "1.23.0")] +impl<'a> From<&'a CStr> for Rc<CStr> { + #[inline] + fn from(s: &CStr) -> Rc<CStr> { + let rc: Rc<[u8]> = Rc::from(s.to_bytes_with_nul()); + unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) } + } +} + #[stable(feature = "default_box_extra", since = "1.17.0")] impl Default for Box<CStr> { fn default() -> Box<CStr> { let boxed: Box<[u8]> = Box::from([0]); - unsafe { mem::transmute(boxed) } + unsafe { Box::from_raw(Box::into_raw(boxed) as *mut CStr) } } } impl NulError { - /// Returns the position of the nul byte in the slice that was provided to - /// [`CString::new`]. + /// Returns the position of the nul byte in the slice that caused + /// [`CString::new`] to fail. /// /// [`CString::new`]: struct.CString.html#method.new /// @@ -711,9 +864,9 @@ impl fmt::Display for IntoStringError { } impl CStr { - /// Casts a raw C string to a safe C string wrapper. + /// Wraps a raw C string with a safe C string wrapper. /// - /// This function will cast the provided `ptr` to the `CStr` wrapper which + /// This function will wrap the provided `ptr` with a `CStr` wrapper, which /// allows inspection and interoperation of non-owned C strings. This method /// is unsafe for a number of reasons: /// @@ -746,16 +899,16 @@ impl CStr { /// ``` #[stable(feature = "rust1", since = "1.0.0")] pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr { - let len = libc::strlen(ptr); + let len = sys::strlen(ptr); let ptr = ptr as *const u8; CStr::from_bytes_with_nul_unchecked(slice::from_raw_parts(ptr, len as usize + 1)) } /// Creates a C string wrapper from a byte slice. /// - /// This function will cast the provided `bytes` to a `CStr` wrapper after - /// ensuring that it is null terminated and does not contain any interior - /// nul bytes. + /// This function will cast the provided `bytes` to a `CStr` + /// wrapper after ensuring that the byte slice is nul-terminated + /// and does not contain any interior nul bytes. /// /// # Examples /// @@ -766,7 +919,7 @@ impl CStr { /// assert!(cstr.is_ok()); /// ``` /// - /// Creating a `CStr` without a trailing nul byte is an error: + /// Creating a `CStr` without a trailing nul terminator is an error: /// /// ``` /// use std::ffi::CStr; @@ -800,7 +953,7 @@ impl CStr { /// Unsafely creates a C string wrapper from a byte slice. /// /// This function will cast the provided `bytes` to a `CStr` wrapper without - /// performing any sanity checks. The provided slice must be null terminated + /// performing any sanity checks. The provided slice **must** be nul-terminated /// and not contain any interior nul bytes. /// /// # Examples @@ -817,12 +970,12 @@ impl CStr { #[inline] #[stable(feature = "cstr_from_bytes", since = "1.10.0")] pub unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &CStr { - mem::transmute(bytes) + &*(bytes as *const [u8] as *const CStr) } /// Returns the inner pointer to this C string. /// - /// The returned pointer will be valid for as long as `self` is and points + /// The returned pointer will be valid for as long as `self` is, and points /// to a contiguous region of memory terminated with a 0 byte to represent /// the end of the string. /// @@ -843,9 +996,9 @@ impl CStr { /// ``` /// /// This happens because the pointer returned by `as_ptr` does not carry any - /// lifetime information and the string is deallocated immediately after + /// lifetime information and the [`CString`] is deallocated immediately after /// the `CString::new("Hello").unwrap().as_ptr()` expression is evaluated. - /// To fix the problem, bind the string to a local variable: + /// To fix the problem, bind the `CString` to a local variable: /// /// ```no_run /// use std::ffi::{CString}; @@ -857,6 +1010,11 @@ impl CStr { /// *ptr; /// } /// ``` + /// + /// This way, the lifetime of the `CString` in `hello` encompasses + /// the lifetime of `ptr` and the `unsafe` block. + /// + /// [`CString`]: struct.CString.html #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn as_ptr(&self) -> *const c_char { @@ -865,11 +1023,7 @@ impl CStr { /// Converts this C string to a byte slice. /// - /// This function will calculate the length of this string (which normally - /// requires a linear amount of work to be done) and then return the - /// resulting slice of `u8` elements. - /// - /// The returned slice will **not** contain the trailing nul that this C + /// The returned slice will **not** contain the trailing nul terminator that this C /// string has. /// /// > **Note**: This method is currently implemented as a 0-cost cast, but @@ -894,7 +1048,7 @@ impl CStr { /// Converts this C string to a byte slice containing the trailing 0 byte. /// /// This function is the equivalent of [`to_bytes`] except that it will retain - /// the trailing nul instead of chopping it off. + /// the trailing nul terminator instead of chopping it off. /// /// > **Note**: This method is currently implemented as a 0-cost cast, but /// > it is planned to alter its definition in the future to perform the @@ -913,13 +1067,14 @@ impl CStr { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn to_bytes_with_nul(&self) -> &[u8] { - unsafe { mem::transmute(&self.inner) } + unsafe { &*(&self.inner as *const [c_char] as *const [u8]) } } /// Yields a [`&str`] slice if the `CStr` contains valid UTF-8. /// - /// This function will calculate the length of this string and check for - /// UTF-8 validity, and then return the [`&str`] if it's valid. + /// If the contents of the `CStr` are valid UTF-8 data, this + /// function will return the corresponding [`&str`] slice. Otherwise, + /// it will return an error with details of where UTF-8 validation failed. /// /// > **Note**: This method is currently implemented to check for validity /// > after a 0-cost cast, but it is planned to alter its definition in the @@ -947,10 +1102,12 @@ impl CStr { /// Converts a `CStr` into a [`Cow`]`<`[`str`]`>`. /// - /// This function will calculate the length of this string (which normally - /// requires a linear amount of work to be done) and then return the - /// resulting slice as a [`Cow`]`<`[`str`]`>`, replacing any invalid UTF-8 sequences - /// with `U+FFFD REPLACEMENT CHARACTER`. + /// If the contents of the `CStr` are valid UTF-8 data, this + /// function will return a [`Cow`]`::`[`Borrowed`]`(`[`&str`]`)` + /// with the the corresponding [`&str`] slice. Otherwise, it will + /// replace any invalid UTF-8 sequences with `U+FFFD REPLACEMENT + /// CHARACTER` and return a [`Cow`]`::`[`Owned`]`(`[`String`]`)` + /// with the result. /// /// > **Note**: This method is currently implemented to check for validity /// > after a 0-cost cast, but it is planned to alter its definition in the @@ -958,7 +1115,9 @@ impl CStr { /// > check whenever this method is called. /// /// [`Cow`]: ../borrow/enum.Cow.html + /// [`Borrowed`]: ../borrow/enum.Cow.html#variant.Borrowed /// [`str`]: ../primitive.str.html + /// [`String`]: ../string/struct.String.html /// /// # Examples /// @@ -1005,7 +1164,8 @@ impl CStr { /// ``` #[stable(feature = "into_boxed_c_str", since = "1.20.0")] pub fn into_c_string(self: Box<CStr>) -> CString { - unsafe { mem::transmute(self) } + let raw = Box::into_raw(self) as *mut [u8]; + CString { inner: unsafe { Box::from_raw(raw) } } } } @@ -1079,6 +1239,8 @@ mod tests { use borrow::Cow::{Borrowed, Owned}; use hash::{Hash, Hasher}; use collections::hash_map::DefaultHasher; + use rc::Rc; + use sync::Arc; #[test] fn c_to_rust() { @@ -1215,4 +1377,21 @@ mod tests { let boxed = <Box<CStr>>::default(); assert_eq!(boxed.to_bytes_with_nul(), &[0]); } + + #[test] + fn into_rc() { + let orig: &[u8] = b"Hello, world!\0"; + let cstr = CStr::from_bytes_with_nul(orig).unwrap(); + let rc: Rc<CStr> = Rc::from(cstr); + let arc: Arc<CStr> = Arc::from(cstr); + + assert_eq!(&*rc, cstr); + assert_eq!(&*arc, cstr); + + let rc2: Rc<CStr> = Rc::from(cstr.to_owned()); + let arc2: Arc<CStr> = Arc::from(cstr.to_owned()); + + assert_eq!(&*rc2, cstr); + assert_eq!(&*arc2, cstr); + } } |