1 // Original code (./not_unpin.rs):
2 //
3 // ```rust
4 // #![allow(dead_code)]
5 //
6 // use pin_project::pin_project;
7 //
8 // #[pin_project(!Unpin)]
9 // pub struct Struct<T, U> {
10 // #[pin]
11 // pinned: T,
12 // unpinned: U,
13 // }
14 //
15 // fn main() {
16 // fn _is_unpin<T: Unpin>() {}
17 // // _is_unpin::<Struct<(), ()>>(); //~ ERROR `std::marker::PhantomPinned` cannot be unpinned
18 // }
19 // ```
20
21 #![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
22 #![allow(clippy::needless_lifetimes)]
23
24 use pin_project::pin_project;
25
26 // #[pin_project(!Unpin)]
27 pub struct Struct<T, U> {
28 // #[pin]
29 pinned: T,
30 unpinned: U,
31 }
32
33 const _: () = {
34 pub(crate) struct __StructProjection<'pin, T, U>
35 where
36 Struct<T, U>: 'pin,
37 {
38 pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
39 unpinned: &'pin mut (U),
40 }
41 pub(crate) struct __StructProjectionRef<'pin, T, U>
42 where
43 Struct<T, U>: 'pin,
44 {
45 pinned: ::pin_project::__private::Pin<&'pin (T)>,
46 unpinned: &'pin (U),
47 }
48
49 impl<T, U> Struct<T, U> {
project<'pin>( self: ::pin_project::__private::Pin<&'pin mut Self>, ) -> __StructProjection<'pin, T, U>50 pub(crate) fn project<'pin>(
51 self: ::pin_project::__private::Pin<&'pin mut Self>,
52 ) -> __StructProjection<'pin, T, U> {
53 unsafe {
54 let Self { pinned, unpinned } = self.get_unchecked_mut();
55 __StructProjection {
56 pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
57 unpinned,
58 }
59 }
60 }
project_ref<'pin>( self: ::pin_project::__private::Pin<&'pin Self>, ) -> __StructProjectionRef<'pin, T, U>61 pub(crate) fn project_ref<'pin>(
62 self: ::pin_project::__private::Pin<&'pin Self>,
63 ) -> __StructProjectionRef<'pin, T, U> {
64 unsafe {
65 let Self { pinned, unpinned } = self.get_ref();
66 __StructProjectionRef {
67 pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
68 unpinned,
69 }
70 }
71 }
72 }
73
74 // Ensure that it's impossible to use pin projections on a #[repr(packed)]
75 // struct.
76 //
77 // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/34
78 // for details.
79 #[forbid(safe_packed_borrows)]
__assert_not_repr_packed<T, U>(this: &Struct<T, U>)80 fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
81 let _ = &this.pinned;
82 let _ = &this.unpinned;
83 }
84
85 // Create `Unpin` impl that has trivial `Unpin` bounds.
86 //
87 // See https://github.com/taiki-e/pin-project/issues/102#issuecomment-540472282
88 // for details.
89 impl<'pin, T, U> ::pin_project::__private::Unpin for Struct<T, U> where
90 ::pin_project::__private::Wrapper<'pin, ::pin_project::__private::PhantomPinned>:
91 ::pin_project::__private::Unpin
92 {
93 }
94 // A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
95 //
96 // To ensure that users don't accidentally write a non-functional `UnsafeUnpin`
97 // impls, we emit one ourselves. If the user ends up writing an `UnsafeUnpin`
98 // impl, they'll get a "conflicting implementations of trait" error when
99 // coherence checks are run.
100 #[doc(hidden)]
101 unsafe impl<'pin, T, U> ::pin_project::UnsafeUnpin for Struct<T, U> where
102 ::pin_project::__private::Wrapper<'pin, ::pin_project::__private::PhantomPinned>:
103 ::pin_project::__private::Unpin
104 {
105 }
106
107 // Ensure that struct does not implement `Drop`.
108 //
109 // See ./struct-default-expanded.rs for details.
110 trait StructMustNotImplDrop {}
111 #[allow(clippy::drop_bounds, drop_bounds)]
112 impl<T: ::pin_project::__private::Drop> StructMustNotImplDrop for T {}
113 impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
114 // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
115 // write a non-functional `PinnedDrop` impls.
116 #[doc(hidden)]
117 impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
drop(self: ::pin_project::__private::Pin<&mut Self>)118 unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
119 }
120 };
121
main()122 fn main() {
123 fn _is_unpin<T: Unpin>() {}
124 // _is_unpin::<Struct<(), ()>>(); //~ ERROR `std::marker::PhantomPinned` cannot be unpinned
125 }
126