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// Original code (./struct-default.rs):
//
// ```rust
// #![allow(dead_code)]
//
// use pin_project::pin_project;
//
// #[pin_project]
// struct Struct<T, U> {
// #[pin]
// pinned: T,
// unpinned: U,
// }
//
// fn main() {}
// ```
#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
#![allow(clippy::needless_lifetimes)]
use pin_project::pin_project;
// #[pin_project]
struct Struct<T, U> {
// #[pin]
pinned: T,
unpinned: U,
}
const _: () = {
struct __StructProjection<'pin, T, U>
where
Struct<T, U>: 'pin,
{
pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
unpinned: &'pin mut (U),
}
struct __StructProjectionRef<'pin, T, U>
where
Struct<T, U>: 'pin,
{
pinned: ::pin_project::__private::Pin<&'pin (T)>,
unpinned: &'pin (U),
}
impl<T, U> Struct<T, U> {
fn project<'pin>(
self: ::pin_project::__private::Pin<&'pin mut Self>,
) -> __StructProjection<'pin, T, U> {
unsafe {
let Self { pinned, unpinned } = self.get_unchecked_mut();
__StructProjection {
pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
unpinned,
}
}
}
fn project_ref<'pin>(
self: ::pin_project::__private::Pin<&'pin Self>,
) -> __StructProjectionRef<'pin, T, U> {
unsafe {
let Self { pinned, unpinned } = self.get_ref();
__StructProjectionRef {
pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
unpinned,
}
}
}
}
// Ensure that it's impossible to use pin projections on a #[repr(packed)]
// struct.
//
// Taking a reference to a packed field is UB, and applying
// `#[forbid(unaligned_references)]` makes sure that doing this is a hard error.
//
// If the struct ends up having #[repr(packed)] applied somehow,
// this will generate an (unfriendly) error message. Under all reasonable
// circumstances, we'll detect the #[repr(packed)] attribute, and generate
// a much nicer error above.
//
// See https://github.com/taiki-e/pin-project/pull/34 for more details.
#[forbid(unaligned_references, safe_packed_borrows)]
fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
let _ = &this.pinned;
let _ = &this.unpinned;
}
// Automatically create the appropriate conditional `Unpin` implementation.
//
// Basically this is equivalent to the following code:
//
// ```rust
// impl<T, U> Unpin for Struct<T, U> where T: Unpin {}
// ```
//
// However, if struct is public and there is a private type field,
// this would cause an E0446 (private type in public interface).
//
// When RFC 2145 is implemented (rust-lang/rust#48054),
// this will become a lint, rather then a hard error.
//
// As a workaround for this, we generate a new struct, containing all of
// the pinned fields from our #[pin_project] type. This struct is declared
// within a function, which makes it impossible to be named by user code.
// This guarantees that it will use the default auto-trait impl for Unpin -
// that is, it will implement Unpin iff all of its fields implement Unpin.
// This type can be safely declared as 'public', satisfying the privacy
// checker without actually allowing user code to access it.
//
// This allows users to apply the #[pin_project] attribute to types
// regardless of the privacy of the types of their fields.
//
// See also https://github.com/taiki-e/pin-project/pull/53.
struct __Struct<'pin, T, U> {
__pin_project_use_generics: ::pin_project::__private::AlwaysUnpin<
'pin,
(::pin_project::__private::PhantomData<T>, ::pin_project::__private::PhantomData<U>),
>,
__field0: T,
}
impl<'pin, T, U> ::pin_project::__private::Unpin for Struct<T, U> where
__Struct<'pin, T, U>: ::pin_project::__private::Unpin
{
}
// A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
//
// To ensure that users don't accidentally write a non-functional `UnsafeUnpin`
// impls, we emit one ourselves. If the user ends up writing an `UnsafeUnpin`
// impl, they'll get a "conflicting implementations of trait" error when
// coherence checks are run.
#[doc(hidden)]
unsafe impl<'pin, T, U> ::pin_project::UnsafeUnpin for Struct<T, U> where
__Struct<'pin, T, U>: ::pin_project::__private::Unpin
{
}
// Ensure that struct does not implement `Drop`.
//
// If you attempt to provide an Drop impl, the blanket impl will
// then apply to your type, causing a compile-time error due to
// the conflict with the second impl.
trait StructMustNotImplDrop {}
#[allow(clippy::drop_bounds, drop_bounds)]
impl<T: ::pin_project::__private::Drop> StructMustNotImplDrop for T {}
impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
// A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
// write a non-functional `PinnedDrop` impls.
#[doc(hidden)]
impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
}
};
fn main() {}
|
