Rollup merge of #52340 - cypher:document-from-trait-in-ffi, r=steveklabnik

Document From trait implementations for OsStr, OsString, CString, and CStr

As part of issue #51430 (cc @skade).

The allocation and copy claims should be double-checked.

r? @steveklabnik
This commit is contained in:
Pietro Albini 2018-08-01 10:12:32 +02:00 committed by GitHub
commit b7ee110ea2
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2 changed files with 48 additions and 0 deletions

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@ -642,6 +642,12 @@ impl fmt::Debug for CString {
#[stable(feature = "cstring_into", since = "1.7.0")]
impl From<CString> for Vec<u8> {
/// Converts a [`CString`] into a [`Vec`]`<u8>`.
///
/// The conversion consumes the [`CString`], and removes the terminating NUL byte.
///
/// [`Vec`]: ../vec/struct.Vec.html
/// [`CString`]: ../ffi/struct.CString.html
#[inline]
fn from(s: CString) -> Vec<u8> {
s.into_bytes()
@ -700,6 +706,10 @@ impl<'a> From<&'a CStr> for Box<CStr> {
#[stable(feature = "c_string_from_box", since = "1.18.0")]
impl From<Box<CStr>> for CString {
/// Converts a [`Box`]`<CStr>` into a [`CString`] without copying or allocating.
///
/// [`Box`]: ../boxed/struct.Box.html
/// [`CString`]: ../ffi/struct.CString.html
#[inline]
fn from(s: Box<CStr>) -> CString {
s.into_c_string()
@ -716,6 +726,10 @@ impl Clone for Box<CStr> {
#[stable(feature = "box_from_c_string", since = "1.20.0")]
impl From<CString> for Box<CStr> {
/// Converts a [`CString`] into a [`Box`]`<CStr>` without copying or allocating.
///
/// [`CString`]: ../ffi/struct.CString.html
/// [`Box`]: ../boxed/struct.Box.html
#[inline]
fn from(s: CString) -> Box<CStr> {
s.into_boxed_c_str()
@ -748,6 +762,10 @@ impl<'a> From<&'a CString> for Cow<'a, CStr> {
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<CString> for Arc<CStr> {
/// Converts a [`CString`] into a [`Arc`]`<CStr>` without copying or allocating.
///
/// [`CString`]: ../ffi/struct.CString.html
/// [`Arc`]: ../sync/struct.Arc.html
#[inline]
fn from(s: CString) -> Arc<CStr> {
let arc: Arc<[u8]> = Arc::from(s.into_inner());
@ -766,6 +784,10 @@ impl<'a> From<&'a CStr> for Arc<CStr> {
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<CString> for Rc<CStr> {
/// Converts a [`CString`] into a [`Rc`]`<CStr>` without copying or allocating.
///
/// [`CString`]: ../ffi/struct.CString.html
/// [`Rc`]: ../rc/struct.Rc.html
#[inline]
fn from(s: CString) -> Rc<CStr> {
let rc: Rc<[u8]> = Rc::from(s.into_inner());
@ -839,6 +861,10 @@ impl fmt::Display for NulError {
#[stable(feature = "rust1", since = "1.0.0")]
impl From<NulError> for io::Error {
/// Converts a [`NulError`] into a [`io::Error`].
///
/// [`NulError`]: ../ffi/struct.NulError.html
/// [`io::Error`]: ../io/struct.Error.html
fn from(_: NulError) -> io::Error {
io::Error::new(io::ErrorKind::InvalidInput,
"data provided contains a nul byte")

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@ -348,6 +348,12 @@ impl OsString {
#[stable(feature = "rust1", since = "1.0.0")]
impl From<String> for OsString {
/// Converts a [`String`] into a [`OsString`].
///
/// The conversion copies the data, and includes an allocation on the heap.
///
/// [`String`]: ../string/struct.String.html
/// [`OsString`]: struct.OsString.html
fn from(s: String) -> OsString {
OsString { inner: Buf::from_string(s) }
}
@ -630,6 +636,10 @@ impl<'a> From<&'a OsStr> for Box<OsStr> {
#[stable(feature = "os_string_from_box", since = "1.18.0")]
impl From<Box<OsStr>> for OsString {
/// Converts a `Box<OsStr>` into a `OsString` without copying or allocating.
///
/// [`Box`]: ../boxed/struct.Box.html
/// [`OsString`]: ../ffi/struct.OsString.html
fn from(boxed: Box<OsStr>) -> OsString {
boxed.into_os_string()
}
@ -637,6 +647,10 @@ impl From<Box<OsStr>> for OsString {
#[stable(feature = "box_from_os_string", since = "1.20.0")]
impl From<OsString> for Box<OsStr> {
/// Converts a [`OsString`] into a [`Box`]`<OsStr>` without copying or allocating.
///
/// [`Box`]: ../boxed/struct.Box.html
/// [`OsString`]: ../ffi/struct.OsString.html
fn from(s: OsString) -> Box<OsStr> {
s.into_boxed_os_str()
}
@ -652,6 +666,10 @@ impl Clone for Box<OsStr> {
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<OsString> for Arc<OsStr> {
/// Converts a [`OsString`] into a [`Arc`]`<OsStr>` without copying or allocating.
///
/// [`Arc`]: ../sync/struct.Arc.html
/// [`OsString`]: ../ffi/struct.OsString.html
#[inline]
fn from(s: OsString) -> Arc<OsStr> {
let arc = s.inner.into_arc();
@ -670,6 +688,10 @@ impl<'a> From<&'a OsStr> for Arc<OsStr> {
#[stable(feature = "shared_from_slice2", since = "1.24.0")]
impl From<OsString> for Rc<OsStr> {
/// Converts a [`OsString`] into a [`Rc`]`<OsStr>` without copying or allocating.
///
/// [`Rc`]: ../rc/struct.Rc.html
/// [`OsString`]: ../ffi/struct.OsString.html
#[inline]
fn from(s: OsString) -> Rc<OsStr> {
let rc = s.inner.into_rc();