1use std::{
2 ffi::c_int,
3 io,
4 ops::{Deref, DerefMut},
5 ptr::NonNull,
6};
7
8pub struct Immutable<T: ?Sized>(pub(crate) T);
12
13impl<T> Immutable<T> {
14 pub fn value(&self) -> &T {
15 &self.0
16 }
17}
18
19impl<T> Deref for Immutable<T> {
20 type Target = T;
21
22 fn deref(&self) -> &Self::Target {
23 &self.0
24 }
25}
26
27impl<T: core::fmt::Debug> core::fmt::Debug for Immutable<T> {
28 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
29 f.debug_tuple("Immutable").field(&self.0).finish()
30 }
31}
32
33pub trait UniquePtrTarget: Sized {
35 unsafe fn ptr_new() -> *mut Self;
41 unsafe fn ptr_drop(ptr: *mut Self);
47}
48
49pub struct UniquePtr<T: UniquePtrTarget> {
51 ptr: NonNull<T>,
52}
53
54impl<T: UniquePtrTarget> UniquePtr<T> {
55 pub fn new() -> Self {
56 Self {
57 ptr: NonNull::new(unsafe { T::ptr_new() }).unwrap(),
58 }
59 }
60}
61
62impl<T: UniquePtrTarget> Default for UniquePtr<T> {
63 fn default() -> Self {
64 Self::new()
65 }
66}
67
68impl<T: UniquePtrTarget> Deref for UniquePtr<T> {
69 type Target = T;
70
71 fn deref(&self) -> &Self::Target {
72 unsafe { &*(self.ptr.as_ptr() as *const T) }
73 }
74}
75
76impl<T: UniquePtrTarget> DerefMut for UniquePtr<T> {
77 fn deref_mut(&mut self) -> &mut Self::Target {
78 unsafe { &mut *(self.ptr.as_mut() as *mut T) }
79 }
80}
81
82impl<T: UniquePtrTarget> Drop for UniquePtr<T> {
83 fn drop(&mut self) {
84 unsafe { T::ptr_drop(self.ptr.as_mut()) }
85 }
86}
87
88impl<T: UniquePtrTarget + core::fmt::Debug> core::fmt::Debug for UniquePtr<T> {
89 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
90 self.deref().fmt(f)
91 }
92}
93
94#[inline]
95pub fn handle_result(ret: c_int) -> io::Result<()> {
96 if ret < 0 {
97 Err(io::Error::from_raw_os_error(ret))
98 } else {
99 Ok(())
100 }
101}