user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

constify CStr methods

Browse source
This commit is contained in:
Maybe Waffle 2022-08-09 03:20:15 +04:00
parent 9bbbf60b04
commit cb02b647dc
3 changed files with 37 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

19
library/core/src/ffi/c_str.rs
View file

@ -121,10 +121,10 @@ enum FromBytesWithNulErrorKind {
}
impl FromBytesWithNulError {
fn interior_nul(pos: usize) -> FromBytesWithNulError {
const fn interior_nul(pos: usize) -> FromBytesWithNulError {
FromBytesWithNulError { kind: FromBytesWithNulErrorKind::InteriorNul(pos) }
}
fn not_nul_terminated() -> FromBytesWithNulError {
const fn not_nul_terminated() -> FromBytesWithNulError {
FromBytesWithNulError { kind: FromBytesWithNulErrorKind::NotNulTerminated }
}
@ -299,7 +299,8 @@ impl CStr {
/// ```
///
#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
pub fn from_bytes_until_nul(bytes: &[u8]) -> Result<&CStr, FromBytesUntilNulError> {
#[rustc_const_unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
pub const fn from_bytes_until_nul(bytes: &[u8]) -> Result<&CStr, FromBytesUntilNulError> {
let nul_pos = memchr::memchr(0, bytes);
match nul_pos {
Some(nul_pos) => {
@ -348,7 +349,8 @@ impl CStr {
/// assert!(cstr.is_err());
/// ```
#[stable(feature = "cstr_from_bytes", since = "1.10.0")]
pub fn from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, FromBytesWithNulError> {
#[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")]
pub const fn from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, FromBytesWithNulError> {
let nul_pos = memchr::memchr(0, bytes);
match nul_pos {
Some(nul_pos) if nul_pos + 1 == bytes.len() => {
@ -497,7 +499,8 @@ impl CStr {
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn to_bytes(&self) -> &[u8] {
#[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")]
pub const fn to_bytes(&self) -> &[u8] {
let bytes = self.to_bytes_with_nul();
// SAFETY: to_bytes_with_nul returns slice with length at least 1
unsafe { bytes.get_unchecked(..bytes.len() - 1) }
@ -524,7 +527,8 @@ impl CStr {
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn to_bytes_with_nul(&self) -> &[u8] {
#[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")]
pub const fn to_bytes_with_nul(&self) -> &[u8] {
// SAFETY: Transmuting a slice of `c_char`s to a slice of `u8`s
// is safe on all supported targets.
unsafe { &*(&self.inner as *const [c_char] as *const [u8]) }
@ -547,7 +551,8 @@ impl CStr {
/// assert_eq!(cstr.to_str(), Ok("foo"));
/// ```
#[stable(feature = "cstr_to_str", since = "1.4.0")]
pub fn to_str(&self) -> Result<&str, str::Utf8Error> {
#[rustc_const_unstable(feature = "const_cstr_methods", issue = "101719")]
pub const fn to_str(&self) -> Result<&str, str::Utf8Error> {
// N.B., when `CStr` is changed to perform the length check in `.to_bytes()`
// instead of in `from_ptr()`, it may be worth considering if this should
// be rewritten to do the UTF-8 check inline with the length calculation