Struct chromium::StableString

#[repr(C)]
pub struct StableString { /* fields omitted */ }

A struct for the parts of a String with a stable layout.

Unsafety

Because this type is primarily intended to help unsafe Rust we should discuss the precise guarantees offered:

• Validity Invariants
  • The data layout is a *mut T, usize, usize.
• Soundness Invariants
  • The *mut T must point to the start of a valid String allocation.
  • The first usize must be the correct length of that valid String.
  • The second usize must be the correct capacity of that valid String.
  • The memory is owned by the String and is allocated from Rust's Global Allocator.
    • You must not turn this type back into a String in a Rust runtime with a different global allocator than the one is was created with. At the moment (2020-03-06) it happens to be the case that the default Rust global allocator is process-wide on Windows / Mac / Linux.
  • The memory must contain valid UTF-8 data.

If you drop a StableString without turning it back into a StableString then the memory leaks.

#include <stdint.h>
// Identical layout to `StableString`
typedef struct {
  uint8_t *ptr;
  uintptr_t len;
  uintptr_t cap;
} StableString;

Trait Implementations

impl Debug for StableString

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

Debug prints as a slice would.

impl Default for StableString

fn default() -> Self

Defaults to an empty vec.

let sv: StableString = StableString::default();
assert_eq!(sv.len(), 0);

impl Deref for StableString

type Target = str

The resulting type after dereferencing.

fn deref(&self) -> &str

Dereferences the value.

impl DerefMut for StableString

fn deref_mut(&mut self) -> &mut str

Mutably dereferences the value.

impl From<StableString> for String

fn from(sv: StableString) -> Self

Performs the conversion.

impl From<String> for StableString

fn from(s: String) -> Self

Performs the conversion.

impl StableLayout for StableString