mirror of https://github.com/rust-lang/rust.git
79 lines
1.7 KiB
Rust
79 lines
1.7 KiB
Rust
//@ check-pass
|
|
|
|
#![feature(derive_smart_pointer)]
|
|
|
|
#[derive(core::marker::SmartPointer)]
|
|
#[repr(transparent)]
|
|
pub struct Ptr<'a, #[pointee] T: OnDrop + ?Sized, X> {
|
|
data: &'a mut T,
|
|
x: core::marker::PhantomData<X>,
|
|
}
|
|
|
|
pub trait OnDrop {
|
|
fn on_drop(&mut self);
|
|
}
|
|
|
|
#[derive(core::marker::SmartPointer)]
|
|
#[repr(transparent)]
|
|
pub struct Ptr2<'a, #[pointee] T: ?Sized, X>
|
|
where
|
|
T: OnDrop,
|
|
{
|
|
data: &'a mut T,
|
|
x: core::marker::PhantomData<X>,
|
|
}
|
|
|
|
pub trait MyTrait<T: ?Sized> {}
|
|
|
|
#[derive(core::marker::SmartPointer)]
|
|
#[repr(transparent)]
|
|
pub struct Ptr3<'a, #[pointee] T: ?Sized, X>
|
|
where
|
|
T: MyTrait<T>,
|
|
{
|
|
data: &'a mut T,
|
|
x: core::marker::PhantomData<X>,
|
|
}
|
|
|
|
#[derive(core::marker::SmartPointer)]
|
|
#[repr(transparent)]
|
|
pub struct Ptr4<'a, #[pointee] T: MyTrait<T> + ?Sized, X> {
|
|
data: &'a mut T,
|
|
x: core::marker::PhantomData<X>,
|
|
}
|
|
|
|
#[derive(core::marker::SmartPointer)]
|
|
#[repr(transparent)]
|
|
pub struct Ptr5<'a, #[pointee] T: ?Sized, X>
|
|
where
|
|
Ptr5Companion<T>: MyTrait<T>,
|
|
Ptr5Companion2: MyTrait<T>,
|
|
{
|
|
data: &'a mut T,
|
|
x: core::marker::PhantomData<X>,
|
|
}
|
|
|
|
pub struct Ptr5Companion<T: ?Sized>(core::marker::PhantomData<T>);
|
|
pub struct Ptr5Companion2;
|
|
|
|
#[derive(core::marker::SmartPointer)]
|
|
#[repr(transparent)]
|
|
pub struct Ptr6<'a, #[pointee] T: ?Sized, X: MyTrait<T> = (), const PARAM: usize = 0> {
|
|
data: &'a mut T,
|
|
x: core::marker::PhantomData<X>,
|
|
}
|
|
|
|
// a reduced example from https://lore.kernel.org/all/20240402-linked-list-v1-1-b1c59ba7ae3b@google.com/
|
|
#[repr(transparent)]
|
|
#[derive(core::marker::SmartPointer)]
|
|
pub struct ListArc<#[pointee] T, const ID: u64 = 0>
|
|
where
|
|
T: ListArcSafe<ID> + ?Sized,
|
|
{
|
|
arc: *const T,
|
|
}
|
|
|
|
pub trait ListArcSafe<const ID: u64> {}
|
|
|
|
fn main() {}
|