core/intrinsics/
bounds.rs

1//! Various traits used to restrict intrinsics to not-completely-wrong types.
2
3use crate::marker::PointeeSized;
4
5/// Types with a built-in dereference operator in runtime MIR,
6/// aka references and raw pointers.
7///
8/// # Safety
9/// Must actually *be* such a type.
10pub unsafe trait BuiltinDeref: Sized {
11    type Pointee: PointeeSized;
12}
13
14unsafe impl<T: PointeeSized> BuiltinDeref for &mut T {
15    type Pointee = T;
16}
17unsafe impl<T: PointeeSized> BuiltinDeref for &T {
18    type Pointee = T;
19}
20unsafe impl<T: PointeeSized> BuiltinDeref for *mut T {
21    type Pointee = T;
22}
23unsafe impl<T: PointeeSized> BuiltinDeref for *const T {
24    type Pointee = T;
25}
26
27#[cfg(not(feature = "ferrocene_certified"))]
28pub trait ChangePointee<U: PointeeSized>: BuiltinDeref {
29    type Output;
30}
31#[cfg(not(feature = "ferrocene_certified"))]
32impl<'a, T: PointeeSized + 'a, U: PointeeSized + 'a> ChangePointee<U> for &'a mut T {
33    type Output = &'a mut U;
34}
35#[cfg(not(feature = "ferrocene_certified"))]
36impl<'a, T: PointeeSized + 'a, U: PointeeSized + 'a> ChangePointee<U> for &'a T {
37    type Output = &'a U;
38}
39#[cfg(not(feature = "ferrocene_certified"))]
40impl<T: PointeeSized, U: PointeeSized> ChangePointee<U> for *mut T {
41    type Output = *mut U;
42}
43#[cfg(not(feature = "ferrocene_certified"))]
44impl<T: PointeeSized, U: PointeeSized> ChangePointee<U> for *const T {
45    type Output = *const U;
46}