Struct c_string::OwnedCString
[−]
[src]
pub struct OwnedCString { /* fields omitted */ }
Representation of an allocated C String.
This structure wraps a raw pointer to a null-terminated C string and a destructor function to invoke when dropped.
Methods
impl OwnedCString
[src]
unsafe fn new(ptr: *const c_char, dtor: DestroyFn) -> OwnedCString
Create an OwnedCString
from a raw pointer and a destructor.
The destructor will be invoked when the OwnedCString
is dropped.
Panics
Panics if ptr
is null.
Methods from Deref<Target = CStr>
fn as_ptr(&self) -> *const i8
1.0.0
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
behaviour when ptr
is used inside the unsafe
block:
use std::ffi::{CString}; let ptr = CString::new("Hello").unwrap().as_ptr(); unsafe { // `ptr` is dangling *ptr; }
This happens because the pointer returned by as_ptr
does not carry any
lifetime information and the string 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:
use std::ffi::{CString}; let hello = CString::new("Hello").unwrap(); let ptr = hello.as_ptr(); unsafe { // `ptr` is valid because `hello` is in scope *ptr; }
fn to_bytes(&self) -> &[u8]
1.0.0
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 string has.
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.
fn to_bytes_with_nul(&self) -> &[u8]
1.0.0
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.
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.
fn to_str(&self) -> Result<&str, Utf8Error>
1.4.0
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.
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 future to perform the length calculation in addition to the UTF-8 check whenever this method is called.
fn to_string_lossy(&self) -> Cow<str>
1.4.0
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
.
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 future to perform the length calculation in addition to the UTF-8 check whenever this method is called.
fn into_c_string(self: Box<CStr>) -> CString
into_boxed_c_str
)Trait Implementations
impl Drop for OwnedCString
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impl Deref for OwnedCString
[src]
type Target = CStr
The resulting type after dereferencing
fn deref(&self) -> &CStr
The method called to dereference a value
impl PartialEq for OwnedCString
[src]
fn eq(&self, other: &OwnedCString) -> bool
This method tests for self
and other
values to be equal, and is used by ==
. Read more
fn ne(&self, other: &Rhs) -> bool
1.0.0
This method tests for !=
.
impl Eq for OwnedCString
[src]
impl PartialOrd for OwnedCString
[src]
fn partial_cmp(&self, other: &OwnedCString) -> Option<Ordering>
This method returns an ordering between self
and other
values if one exists. Read more
fn lt(&self, other: &Rhs) -> bool
1.0.0
This method tests less than (for self
and other
) and is used by the <
operator. Read more
fn le(&self, other: &Rhs) -> bool
1.0.0
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
fn gt(&self, other: &Rhs) -> bool
1.0.0
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
fn ge(&self, other: &Rhs) -> bool
1.0.0
This method tests greater than or equal to (for self
and other
) and is used by the >=
operator. Read more
impl Ord for OwnedCString
[src]
fn cmp(&self, other: &OwnedCString) -> Ordering
This method returns an Ordering
between self
and other
. Read more
impl Hash for OwnedCString
[src]
fn hash<H>(&self, state: &mut H) where
H: Hasher,
H: Hasher,
Feeds this value into the given [Hasher
]. Read more
fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,
1.3.0
H: Hasher,
Feeds a slice of this type into the given [Hasher
]. Read more