1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91

use std::num::{
    NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroIsize, NonZeroU128,
    NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize,
};
use std::path::{Path, PathBuf};
use std::rc::Rc;
use std::sync::atomic::{
    AtomicBool, AtomicI16, AtomicI32, AtomicI64, AtomicI8, AtomicIsize, AtomicU16, AtomicU32,
    AtomicU64, AtomicU8, AtomicUsize,
};

/// The Trace trait, which needs to be implemented on garbage-collected objects.
#[allow(clippy::missing_safety_doc)]
pub unsafe trait Trace {
    /// Marks all contained `Gc`s.
    unsafe fn trace(&self);

    /// Is this object marked.
    #[inline]
    unsafe fn marked(&self) -> bool {
        false
    }
}

#[macro_export]
macro_rules! empty_trace {
    () => {
        #[inline]
        unsafe fn trace(&self) {}
    };
}

unsafe impl<T: ?Sized> Trace for &'static T {
    empty_trace!();
}

macro_rules! simple_empty_trace {
    ($($T:ty),*) => {
        $(
            unsafe impl Trace for $T { empty_trace!(); }
        )*
    };
}

simple_empty_trace![
    (),
    bool,
    isize,
    usize,
    i8,
    u8,
    i16,
    u16,
    i32,
    u32,
    i64,
    u64,
    i128,
    u128,
    f32,
    f64,
    char,
    String,
    Box<str>,
    Rc<str>,
    Path,
    PathBuf,
    NonZeroIsize,
    NonZeroUsize,
    NonZeroI8,
    NonZeroU8,
    NonZeroI16,
    NonZeroU16,
    NonZeroI32,
    NonZeroU32,
    NonZeroI64,
    NonZeroU64,
    NonZeroI128,
    NonZeroU128,
    AtomicBool,
    AtomicIsize,
    AtomicUsize,
    AtomicI8,
    AtomicU8,
    AtomicI16,
    AtomicU16,
    AtomicI32,
    AtomicU32,
    AtomicI64,
    AtomicU64
];