std_traits/
ptr.rs

1use core::fmt::Debug;
2
3use crate::{num::Integer, primitive::Primitive, reference::Mutability, util::cast_int};
4
5macro_rules! cast_ptr {
6    ($T:ty, $P:ty, $value:expr) => {
7        match <$P>::ptr_type() {
8            $crate::reference::Mutability::Const => unsafe {
9                $crate::util::transmute_unchecked::<*const $T, $P>($value as *const $T)
10            },
11            $crate::reference::Mutability::Mut => unsafe {
12                $crate::util::transmute_unchecked::<*mut $T, $P>($value as *mut $T)
13            },
14        }
15    };
16}
17
18pub(crate) use cast_ptr;
19
20pub trait Pointer<T: ?Sized>: Primitive + Copy + Debug + Sized {
21    fn ptr_type() -> Mutability;
22
23    fn cast_ptr<U: Sized, P: Pointer<U>>(self) -> P
24    where
25        Self: Sized;
26
27    fn cast_int<I: Integer>(self) -> I
28    where
29        T: Sized;
30}
31
32macro_rules! impl_pointer {
33    ($mut:tt, $ty:expr) => {
34        impl<T: ?Sized> Primitive for *$mut T {}
35
36        impl<T: ?Sized> Pointer<T> for *$mut T {
37            fn ptr_type() -> Mutability {
38                $ty
39            }
40
41            fn cast_ptr<U: Sized, P: Pointer<U>>(self) -> P where Self: Sized {
42                cast_ptr!(T, P, self)
43            }
44
45            fn cast_int<I: Integer>(self) -> I where T: Sized {
46                cast_int!(self => I)
47            }
48        }
49    }
50}
51
52impl_pointer!(const, Mutability::Const);
53impl_pointer!(mut, Mutability::Mut);
54
55#[cfg(test)]
56mod test {
57    use super::*;
58
59    #[test]
60    fn test_cast() {
61        let ptr: *const u8 = "foo".as_ptr();
62        let int: usize = ptr.cast_int();
63        let ptr2: *const u8 = int.cast_ptr();
64
65        assert_eq!(ptr, ptr2);
66    }
67}
std_traits/ptr.rs

std_traits/
ptr.rs
