style_traits/
owned_str.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5#![allow(unsafe_code)]
6
7//! A replacement for `Box<str>` that has a defined layout for FFI.
8
9use crate::owned_slice::OwnedSlice;
10use std::fmt;
11use std::ops::{Deref, DerefMut};
12
13/// A struct that basically replaces a Box<str>, but with a defined layout,
14/// suitable for FFI.
15#[repr(C)]
16#[derive(Clone, Default, Eq, MallocSizeOf, PartialEq, ToShmem)]
17pub struct OwnedStr(OwnedSlice<u8>);
18
19impl fmt::Debug for OwnedStr {
20    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
21        self.deref().fmt(formatter)
22    }
23}
24
25impl Deref for OwnedStr {
26    type Target = str;
27
28    #[inline(always)]
29    fn deref(&self) -> &Self::Target {
30        unsafe { std::str::from_utf8_unchecked(&*self.0) }
31    }
32}
33
34impl DerefMut for OwnedStr {
35    #[inline(always)]
36    fn deref_mut(&mut self) -> &mut Self::Target {
37        unsafe { std::str::from_utf8_unchecked_mut(&mut *self.0) }
38    }
39}
40
41impl OwnedStr {
42    /// Convert the OwnedStr into a boxed str.
43    #[inline]
44    pub fn into_box(self) -> Box<str> {
45        self.into_string().into_boxed_str()
46    }
47
48    /// Convert the OwnedStr into a `String`.
49    #[inline]
50    pub fn into_string(self) -> String {
51        unsafe { String::from_utf8_unchecked(self.0.into_vec()) }
52    }
53}
54
55impl From<OwnedStr> for String {
56    #[inline]
57    fn from(b: OwnedStr) -> Self {
58        b.into_string()
59    }
60}
61
62impl From<OwnedStr> for Box<str> {
63    #[inline]
64    fn from(b: OwnedStr) -> Self {
65        b.into_box()
66    }
67}
68
69impl From<Box<str>> for OwnedStr {
70    #[inline]
71    fn from(b: Box<str>) -> Self {
72        Self::from(b.into_string())
73    }
74}
75
76impl From<String> for OwnedStr {
77    #[inline]
78    fn from(s: String) -> Self {
79        OwnedStr(s.into_bytes().into())
80    }
81}
style_traits/owned_str.rs

style_traits/
owned_str.rs
