Struct sgx_trts::c_str::CStr

pub struct CStr { /* fields omitted */ }

Representation of a borrowed C string.

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 functions may leverage the unsafe [from_ptr] constructor to provide a safe interface to other consumers.

Methods

impl CStr

pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr

Wraps a raw C string with a safe C string wrapper.

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:

• There is no guarantee to the validity of ptr.
• The returned lifetime is not guaranteed to be the actual lifetime of ptr.
• There is no guarantee that the memory pointed to by ptr contains a valid nul terminator byte at the end of the string.
• It is not guaranteed that the memory pointed by ptr won't change before the CStr has been destroyed.

Note: This operation is intended to be a 0-cost cast but it is currently implemented with an up-front calculation of the length of the string. This is not guaranteed to always be the case.

pub fn from_bytes_with_nul(bytes: &[u8]) -> Result<&CStr, FromBytesWithNulError>

Creates a C string wrapper from a byte slice.

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.

pub const unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &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 nul-terminated and not contain any interior nul bytes.

pub const fn as_ptr(&self) -> *const c_char

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.

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.

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.

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.

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 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.

pub fn into_c_string(self: Box<CStr>) -> CString

Converts a Box<CStr> into a CString without copying or allocating.

Trait Implementations

impl<'_> From<&'_ CStr> for Box<CStr>

fn from(s: &CStr) -> Box<CStr>

Performs the conversion.

impl<'a> From<&'a CStr> for Cow<'a, CStr>

fn from(s: &'a CStr) -> Cow<'a, CStr>

Performs the conversion.

impl<'_> From<&'_ CStr> for Arc<CStr>

fn from(s: &CStr) -> Arc<CStr>

Performs the conversion.

impl<'_> From<&'_ CStr> for Rc<CStr>

fn from(s: &CStr) -> Rc<CStr>

Performs the conversion.

impl<'_> From<&'_ CStr> for CString

fn from(s: &CStr) -> CString

Performs the conversion.

impl PartialEq<CStr> for CStr

fn eq(&self, other: &CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Eq for CStr

impl Ord for CStr

fn cmp(&self, other: &CStr) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialOrd<CStr> for CStr

fn partial_cmp(&self, other: &CStr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use] fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use] fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use] fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use] fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Hash for CStr

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl Debug for CStr

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl AsRef<CStr> for CStr

fn as_ref(&self) -> &CStr

Performs the conversion.

impl AsRef<CStr> for CString

fn as_ref(&self) -> &CStr

Performs the conversion.

impl<'_> Default for &'_ CStr

fn default() -> Self

Returns the "default value" for a type.

impl Borrow<CStr> for CString

fn borrow(&self) -> &CStr

Immutably borrows from an owned value.

impl ToOwned for CStr

type Owned = CString

The resulting type after obtaining ownership.

fn to_owned(&self) -> CString

Creates owned data from borrowed data, usually by cloning.

fn clone_into(&self, target: &mut Self::Owned)

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning.