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-rw-r--r--vendor/futures-task/src/future_obj.rs335
1 files changed, 0 insertions, 335 deletions
diff --git a/vendor/futures-task/src/future_obj.rs b/vendor/futures-task/src/future_obj.rs
deleted file mode 100644
index a6113821..00000000
--- a/vendor/futures-task/src/future_obj.rs
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@@ -1,335 +0,0 @@
-use core::{
- fmt,
- future::Future,
- marker::PhantomData,
- mem,
- pin::Pin,
- task::{Context, Poll},
-};
-
-/// A custom trait object for polling futures, roughly akin to
-/// `Box<dyn Future<Output = T> + 'a>`.
-///
-/// This custom trait object was introduced as currently it is not possible to
-/// take `dyn Trait` by value and `Box<dyn Trait>` is not available in no_std
-/// contexts.
-pub struct LocalFutureObj<'a, T> {
- future: *mut (dyn Future<Output = T> + 'static),
- drop_fn: unsafe fn(*mut (dyn Future<Output = T> + 'static)),
- _marker: PhantomData<&'a ()>,
-}
-
-// As LocalFutureObj only holds pointers, even if we move it, the pointed to values won't move,
-// so this is safe as long as we don't provide any way for a user to directly access the pointers
-// and move their values.
-impl<T> Unpin for LocalFutureObj<'_, T> {}
-
-#[allow(single_use_lifetimes)]
-#[allow(clippy::transmute_ptr_to_ptr)]
-unsafe fn remove_future_lifetime<'a, T>(
- ptr: *mut (dyn Future<Output = T> + 'a),
-) -> *mut (dyn Future<Output = T> + 'static) {
- unsafe { mem::transmute(ptr) }
-}
-
-#[allow(single_use_lifetimes)]
-unsafe fn remove_drop_lifetime<'a, T>(
- ptr: unsafe fn(*mut (dyn Future<Output = T> + 'a)),
-) -> unsafe fn(*mut (dyn Future<Output = T> + 'static)) {
- unsafe { mem::transmute(ptr) }
-}
-
-impl<'a, T> LocalFutureObj<'a, T> {
- /// Create a `LocalFutureObj` from a custom trait object representation.
- #[inline]
- pub fn new<F: UnsafeFutureObj<'a, T> + 'a>(f: F) -> Self {
- Self {
- future: unsafe { remove_future_lifetime(f.into_raw()) },
- drop_fn: unsafe { remove_drop_lifetime(F::drop) },
- _marker: PhantomData,
- }
- }
-
- /// Converts the `LocalFutureObj` into a `FutureObj`.
- ///
- /// # Safety
- ///
- /// To make this operation safe one has to ensure that the `UnsafeFutureObj`
- /// instance from which this `LocalFutureObj` was created actually
- /// implements `Send`.
- #[inline]
- pub unsafe fn into_future_obj(self) -> FutureObj<'a, T> {
- FutureObj(self)
- }
-}
-
-impl<T> fmt::Debug for LocalFutureObj<'_, T> {
- fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- f.debug_struct("LocalFutureObj").finish()
- }
-}
-
-impl<'a, T> From<FutureObj<'a, T>> for LocalFutureObj<'a, T> {
- #[inline]
- fn from(f: FutureObj<'a, T>) -> Self {
- f.0
- }
-}
-
-impl<T> Future for LocalFutureObj<'_, T> {
- type Output = T;
-
- #[inline]
- fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
- unsafe { Pin::new_unchecked(&mut *self.future).poll(cx) }
- }
-}
-
-impl<T> Drop for LocalFutureObj<'_, T> {
- fn drop(&mut self) {
- unsafe { (self.drop_fn)(self.future) }
- }
-}
-
-/// A custom trait object for polling futures, roughly akin to
-/// `Box<dyn Future<Output = T> + Send + 'a>`.
-///
-/// This custom trait object was introduced as currently it is not possible to
-/// take `dyn Trait` by value and `Box<dyn Trait>` is not available in no_std
-/// contexts.
-///
-/// You should generally not need to use this type outside of `no_std` or when
-/// implementing `Spawn`, consider using `BoxFuture` instead.
-pub struct FutureObj<'a, T>(LocalFutureObj<'a, T>);
-
-impl<T> Unpin for FutureObj<'_, T> {}
-unsafe impl<T> Send for FutureObj<'_, T> {}
-
-impl<'a, T> FutureObj<'a, T> {
- /// Create a `FutureObj` from a custom trait object representation.
- #[inline]
- pub fn new<F: UnsafeFutureObj<'a, T> + Send>(f: F) -> Self {
- Self(LocalFutureObj::new(f))
- }
-}
-
-impl<T> fmt::Debug for FutureObj<'_, T> {
- fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- f.debug_struct("FutureObj").finish()
- }
-}
-
-impl<T> Future for FutureObj<'_, T> {
- type Output = T;
-
- #[inline]
- fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
- Pin::new(&mut self.0).poll(cx)
- }
-}
-
-/// A custom implementation of a future trait object for `FutureObj`, providing
-/// a vtable with drop support.
-///
-/// This custom representation is typically used only in `no_std` contexts,
-/// where the default `Box`-based implementation is not available.
-///
-/// # Safety
-///
-/// See the safety notes on individual methods for what guarantees an
-/// implementor must provide.
-pub unsafe trait UnsafeFutureObj<'a, T>: 'a {
- /// Convert an owned instance into a (conceptually owned) fat pointer.
- ///
- /// # Safety
- ///
- /// ## Implementor
- ///
- /// The trait implementor must guarantee that it is safe to convert the
- /// provided `*mut (dyn Future<Output = T> + 'a)` into a `Pin<&mut (dyn
- /// Future<Output = T> + 'a)>` and call methods on it, non-reentrantly,
- /// until `UnsafeFutureObj::drop` is called with it.
- #[allow(clippy::unnecessary_safety_doc)]
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a);
-
- /// Drops the future represented by the given fat pointer.
- ///
- /// # Safety
- ///
- /// ## Implementor
- ///
- /// The trait implementor must guarantee that it is safe to call this
- /// function once per `into_raw` invocation.
- ///
- /// ## Caller
- ///
- /// The caller must ensure:
- ///
- /// * the pointer passed was obtained from an `into_raw` invocation from
- /// this same trait object
- /// * the pointer is not currently in use as a `Pin<&mut (dyn Future<Output
- /// = T> + 'a)>`
- /// * the pointer must not be used again after this function is called
- unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a));
-}
-
-unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for &'a mut F
-where
- F: Future<Output = T> + Unpin + 'a,
-{
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- self as *mut dyn Future<Output = T>
- }
-
- unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
-}
-
-unsafe impl<'a, T> UnsafeFutureObj<'a, T> for &'a mut (dyn Future<Output = T> + Unpin + 'a) {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- self as *mut dyn Future<Output = T>
- }
-
- unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
-}
-
-unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<&'a mut F>
-where
- F: Future<Output = T> + 'a,
-{
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- unsafe { self.get_unchecked_mut() as *mut dyn Future<Output = T> }
- }
-
- unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
-}
-
-unsafe impl<'a, T> UnsafeFutureObj<'a, T> for Pin<&'a mut (dyn Future<Output = T> + 'a)> {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- unsafe { self.get_unchecked_mut() as *mut dyn Future<Output = T> }
- }
-
- unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
-}
-
-#[cfg(feature = "alloc")]
-mod if_alloc {
- use super::*;
- use alloc::boxed::Box;
-
- unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for Box<F>
- where
- F: Future<Output = T> + 'a,
- {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- Box::into_raw(self)
- }
-
- unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
- drop(unsafe { Box::from_raw(ptr.cast::<F>()) })
- }
- }
-
- unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + 'a> {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- Box::into_raw(self)
- }
-
- unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
- drop(unsafe { Box::from_raw(ptr) })
- }
- }
-
- unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + Send + 'a> {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- Box::into_raw(self)
- }
-
- unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
- drop(unsafe { Box::from_raw(ptr) })
- }
- }
-
- unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<Box<F>>
- where
- F: Future<Output = T> + 'a,
- {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- let mut this = mem::ManuallyDrop::new(self);
- unsafe { this.as_mut().get_unchecked_mut() as *mut _ }
- }
-
- unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
- drop(Pin::from(unsafe { Box::from_raw(ptr) }))
- }
- }
-
- unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + 'a>> {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- let mut this = mem::ManuallyDrop::new(self);
- unsafe { this.as_mut().get_unchecked_mut() as *mut _ }
- }
-
- unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
- drop(Pin::from(unsafe { Box::from_raw(ptr) }))
- }
- }
-
- unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + Send + 'a>> {
- fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
- let mut this = mem::ManuallyDrop::new(self);
- unsafe { this.as_mut().get_unchecked_mut() as *mut _ }
- }
-
- unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
- drop(Pin::from(unsafe { Box::from_raw(ptr) }))
- }
- }
-
- impl<'a, F: Future<Output = ()> + Send + 'a> From<Box<F>> for FutureObj<'a, ()> {
- fn from(boxed: Box<F>) -> Self {
- Self::new(boxed)
- }
- }
-
- impl<'a> From<Box<dyn Future<Output = ()> + Send + 'a>> for FutureObj<'a, ()> {
- fn from(boxed: Box<dyn Future<Output = ()> + Send + 'a>) -> Self {
- Self::new(boxed)
- }
- }
-
- impl<'a, F: Future<Output = ()> + Send + 'a> From<Pin<Box<F>>> for FutureObj<'a, ()> {
- fn from(boxed: Pin<Box<F>>) -> Self {
- Self::new(boxed)
- }
- }
-
- impl<'a> From<Pin<Box<dyn Future<Output = ()> + Send + 'a>>> for FutureObj<'a, ()> {
- fn from(boxed: Pin<Box<dyn Future<Output = ()> + Send + 'a>>) -> Self {
- Self::new(boxed)
- }
- }
-
- impl<'a, F: Future<Output = ()> + 'a> From<Box<F>> for LocalFutureObj<'a, ()> {
- fn from(boxed: Box<F>) -> Self {
- Self::new(boxed)
- }
- }
-
- impl<'a> From<Box<dyn Future<Output = ()> + 'a>> for LocalFutureObj<'a, ()> {
- fn from(boxed: Box<dyn Future<Output = ()> + 'a>) -> Self {
- Self::new(boxed)
- }
- }
-
- impl<'a, F: Future<Output = ()> + 'a> From<Pin<Box<F>>> for LocalFutureObj<'a, ()> {
- fn from(boxed: Pin<Box<F>>) -> Self {
- Self::new(boxed)
- }
- }
-
- impl<'a> From<Pin<Box<dyn Future<Output = ()> + 'a>>> for LocalFutureObj<'a, ()> {
- fn from(boxed: Pin<Box<dyn Future<Output = ()> + 'a>>) -> Self {
- Self::new(boxed)
- }
- }
-}
generated by cgit v1.2.3 (git 2.39.1) at 2026-02-03 06:36:04 +0000