[−][src]Struct rustc_data_structures::small_c_str::SmallCStr
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
Like SmallVec but for C strings.
Fields
data: SmallVec<[u8; 36]>
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
Methods
impl SmallCStr
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impl SmallCStr
pub fn new(s: &str) -> SmallCStr
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pub fn new(s: &str) -> SmallCStr
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
pub fn new_with_nul(s: &str) -> SmallCStr
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pub fn new_with_nul(s: &str) -> SmallCStr
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
pub fn as_c_str(&self) -> &CStr
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pub fn as_c_str(&self) -> &CStr
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
pub fn len_with_nul(&self) -> usize
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pub fn len_with_nul(&self) -> usize
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
pub fn spilled(&self) -> bool
[src]
pub fn spilled(&self) -> bool
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
Methods from Deref<Target = CStr>
pub fn as_ptr(&self) -> *const i8
1.0.0[src]
pub fn as_ptr(&self) -> *const i8
Returns the inner pointer to this C string.
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.
WARNING
It is your responsibility to make sure that the underlying memory is not
freed too early. For example, the following code will cause undefined
behavior when ptr
is used inside the unsafe
block:
use std::ffi::{CString}; let ptr = CString::new("Hello").expect("CString::new failed").as_ptr(); unsafe { // `ptr` is dangling *ptr; }
This happens because the pointer returned by as_ptr
does not carry any
lifetime information and the CString
is deallocated immediately after
the CString::new("Hello").expect("CString::new failed").as_ptr()
expression is evaluated.
To fix the problem, bind the CString
to a local variable:
use std::ffi::{CString}; let hello = CString::new("Hello").expect("CString::new failed"); let ptr = hello.as_ptr(); unsafe { // `ptr` is valid because `hello` is in scope *ptr; }
This way, the lifetime of the CString
in hello
encompasses
the lifetime of ptr
and the unsafe
block.
pub fn to_bytes(&self) -> &[u8]
1.0.0[src]
pub fn to_bytes(&self) -> &[u8]
Converts this C string to a byte slice.
The returned slice will not contain the trailing nul terminator that this C string has.
Note: This method is currently implemented as a constant-time cast, but it is planned to alter its definition in the future to perform the length calculation whenever this method is called.
Examples
use std::ffi::CStr; let c_str = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed"); assert_eq!(c_str.to_bytes(), b"foo");
pub fn to_bytes_with_nul(&self) -> &[u8]
1.0.0[src]
pub fn to_bytes_with_nul(&self) -> &[u8]
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 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 length calculation whenever this method is called.
Examples
use std::ffi::CStr; let c_str = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed"); assert_eq!(c_str.to_bytes_with_nul(), b"foo\0");
pub fn to_str(&self) -> Result<&str, Utf8Error>
1.4.0[src]
pub fn to_str(&self) -> Result<&str, Utf8Error>
Yields a &str
slice if the CStr
contains valid UTF-8.
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 constant-time cast, but it is planned to alter its definition in the future to perform the length calculation in addition to the UTF-8 check whenever this method is called.
Examples
use std::ffi::CStr; let c_str = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed"); assert_eq!(c_str.to_str(), Ok("foo"));
pub fn to_string_lossy(&self) -> Cow<str>
1.4.0[src]
pub fn to_string_lossy(&self) -> Cow<str>
Converts a CStr
into a Cow
<
str
>
.
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 constant-time cast, but it is planned to alter its definition in the future to perform the length calculation in addition to the UTF-8 check whenever this method is called.
Examples
Calling to_string_lossy
on a CStr
containing valid UTF-8:
use std::borrow::Cow; use std::ffi::CStr; let c_str = CStr::from_bytes_with_nul(b"Hello World\0") .expect("CStr::from_bytes_with_nul failed"); assert_eq!(c_str.to_string_lossy(), Cow::Borrowed("Hello World"));
Calling to_string_lossy
on a CStr
containing invalid UTF-8:
use std::borrow::Cow; use std::ffi::CStr; let c_str = CStr::from_bytes_with_nul(b"Hello \xF0\x90\x80World\0") .expect("CStr::from_bytes_with_nul failed"); assert_eq!( c_str.to_string_lossy(), Cow::Owned(String::from("Hello �World")) as Cow<str> );
Trait Implementations
impl Clone for SmallCStr
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impl Clone for SmallCStr
fn clone(&self) -> SmallCStr
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fn clone(&self) -> SmallCStr
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
1.0.0[src]
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
impl Deref for SmallCStr
[src]
impl Deref for SmallCStr
Auto Trait Implementations
Blanket Implementations
impl<T> Erased for T
[src]
impl<T> Erased for T
impl<T> Send for T where
T: ?Sized,
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impl<T> Send for T where
T: ?Sized,
impl<T> Sync for T where
T: ?Sized,
[src]
impl<T> Sync for T where
T: ?Sized,
impl<T> ToOwned for T where
T: Clone,
[src]
impl<T> ToOwned for T where
T: Clone,
type Owned = T
fn to_owned(&self) -> T
[src]
fn to_owned(&self) -> T
Creates owned data from borrowed data, usually by cloning. Read more
fn clone_into(&self, target: &mut T)
[src]
fn clone_into(&self, target: &mut T)
🔬 This is a nightly-only experimental API. (toowned_clone_into
)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more
impl<T> From for T
[src]
impl<T> From for T
impl<T, U> Into for T where
U: From<T>,
[src]
impl<T, U> Into for T where
U: From<T>,
impl<T, U> TryFrom for T where
T: From<U>,
[src]
impl<T, U> TryFrom for T where
T: From<U>,
type Error = !
try_from
)The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
[src]
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
try_from
)Performs the conversion.
impl<T> Borrow for T where
T: ?Sized,
[src]
impl<T> Borrow for T where
T: ?Sized,
ⓘImportant traits for &'a mut Rfn borrow(&self) -> &T
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fn borrow(&self) -> &T
Immutably borrows from an owned value. Read more
impl<T, U> TryInto for T where
U: TryFrom<T>,
[src]
impl<T, U> TryInto for T where
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
try_from
)The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
[src]
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
try_from
)Performs the conversion.
impl<T> BorrowMut for T where
T: ?Sized,
[src]
impl<T> BorrowMut for T where
T: ?Sized,
ⓘImportant traits for &'a mut Rfn borrow_mut(&mut self) -> &mut T
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fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<T> Any for T where
T: 'static + ?Sized,
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impl<T> Any for T where
T: 'static + ?Sized,
fn get_type_id(&self) -> TypeId
[src]
fn get_type_id(&self) -> TypeId
🔬 This is a nightly-only experimental API. (get_type_id
)
this method will likely be replaced by an associated static
Gets the TypeId
of self
. Read more
impl<E> SpecializationError for E
[src]
impl<E> SpecializationError for E
fn not_found<S, T>(trait_name: &'static str, method_name: &'static str) -> E where
T: ?Sized,
[src]
fn not_found<S, T>(trait_name: &'static str, method_name: &'static str) -> E where
T: ?Sized,
🔬 This is a nightly-only experimental API. (rustc_private
)
this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml
instead?
Create an error for a missing method specialization. Defaults to panicking with type, trait & method names. S
is the encoder/decoder state type, T
is the type being encoded/decoded, and the arguments are the names of the trait and method that should've been overridden. Read more
impl<T> Erased for T
impl<T> Erased for T