Auto merge of #51504 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 4 pull requests

Successful merges:

 - #50617 (Fix extern prelude failure in rustdoc)
 - #51442 ([futures] add a few blanket impls to std)
 - #51498 (Make parse_ident public)
 - #51502 (Make parse_seq_to_end and parse_path public)

Failed merges:

Author: bors

src/liballoc/boxed.rs

@@ -914,6 +914,24 @@ impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<PinBox<U>> for PinBox<T> {}
 #[unstable(feature = "pin", issue = "49150")]
 impl<T: ?Sized> Unpin for PinBox<T> {}
 
+#[unstable(feature = "futures_api", issue = "50547")]
+impl<'a, F: ?Sized + Future + Unpin> Future for Box<F> {
+    type Output = F::Output;
+
+    fn poll(mut self: PinMut<Self>, cx: &mut Context) -> Poll<Self::Output> {
+        PinMut::new(&mut **self).poll(cx)
+    }
+}
+
+#[unstable(feature = "futures_api", issue = "50547")]
+impl<'a, F: ?Sized + Future> Future for PinBox<F> {
+    type Output = F::Output;
+
+    fn poll(mut self: PinMut<Self>, cx: &mut Context) -> Poll<Self::Output> {
+        self.as_pin_mut().poll(cx)
+    }
+}
+
 #[unstable(feature = "futures_api", issue = "50547")]
 unsafe impl<F: Future<Output = ()> + Send + 'static> UnsafePoll for PinBox<F> {
     fn into_raw(self) -> *mut () {

src/liballoc/lib.rs

@@ -80,6 +80,7 @@
 #![cfg_attr(test, feature(rand, test))]
 #![feature(allocator_api)]
 #![feature(allow_internal_unstable)]
+#![feature(arbitrary_self_types)]
 #![feature(ascii_ctype)]
 #![feature(box_into_raw_non_null)]
 #![feature(box_patterns)]

src/libcore/future.rs

@@ -15,6 +15,7 @@
 //! Asynchronous values.
 
 use mem::PinMut;
+use marker::Unpin;
 use task::{self, Poll};
 
 /// A future represents an asychronous computation.
@@ -91,3 +92,19 @@ pub trait Future {
     /// about the behavior of `poll` after a future has completed.
     fn poll(self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output>;
 }
+
+impl<'a, F: ?Sized + Future + Unpin> Future for &'a mut F {
+    type Output = F::Output;
+
+    fn poll(mut self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output> {
+        F::poll(PinMut::new(&mut **self), cx)
+    }
+}
+
+impl<'a, F: ?Sized + Future> Future for PinMut<'a, F> {
+    type Output = F::Output;
+
+    fn poll(mut self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output> {
+        F::poll((*self).reborrow(), cx)
+    }
+}

src/libcore/task.rs

@@ -32,6 +32,61 @@ pub enum Poll<T> {
     Pending,
 }
 
+impl<T> Poll<T> {
+    /// Change the ready value of this `Poll` with the closure provided
+    pub fn map<U, F>(self, f: F) -> Poll<U>
+        where F: FnOnce(T) -> U
+    {
+        match self {
+            Poll::Ready(t) => Poll::Ready(f(t)),
+            Poll::Pending => Poll::Pending,
+        }
+    }
+
+    /// Returns whether this is `Poll::Ready`
+    pub fn is_ready(&self) -> bool {
+        match *self {
+            Poll::Ready(_) => true,
+            Poll::Pending => false,
+        }
+    }
+
+    /// Returns whether this is `Poll::Pending`
+    pub fn is_pending(&self) -> bool {
+        !self.is_ready()
+    }
+}
+
+impl<T, E> Poll<Result<T, E>> {
+    /// Change the success value of this `Poll` with the closure provided
+    pub fn map_ok<U, F>(self, f: F) -> Poll<Result<U, E>>
+        where F: FnOnce(T) -> U
+    {
+        match self {
+            Poll::Ready(Ok(t)) => Poll::Ready(Ok(f(t))),
+            Poll::Ready(Err(e)) => Poll::Ready(Err(e)),
+            Poll::Pending => Poll::Pending,
+        }
+    }
+
+    /// Change the error value of this `Poll` with the closure provided
+    pub fn map_err<U, F>(self, f: F) -> Poll<Result<T, U>>
+        where F: FnOnce(E) -> U
+    {
+        match self {
+            Poll::Ready(Ok(t)) => Poll::Ready(Ok(t)),
+            Poll::Ready(Err(e)) => Poll::Ready(Err(f(e))),
+            Poll::Pending => Poll::Pending,
+        }
+    }
+}
+
+impl<T> From<T> for Poll<T> {
+    fn from(t: T) -> Poll<T> {
+        Poll::Ready(t)
+    }
+}
+
 /// A `Waker` is a handle for waking up a task by notifying its executor that it
 /// is ready to be run.
 ///

src/librustc/session/config.rs

@@ -494,6 +494,13 @@ impl Input {
             Input::Str { .. } => "rust_out".to_string(),
         }
     }
+
+    pub fn get_input(&mut self) -> Option<&mut String> {
+        match *self {
+            Input::File(_) => None,
+            Input::Str { ref mut input, .. } => Some(input),
+        }
+    }
 }
 
 #[derive(Clone)]

src/librustc_resolve/lib.rs

@@ -1437,6 +1437,9 @@ pub struct Resolver<'a> {
     current_type_ascription: Vec<Span>,
 
     injected_crate: Option<Module<'a>>,
+
+    /// Only supposed to be used by rustdoc, otherwise should be false.
+    pub ignore_extern_prelude_feature: bool,
 }
 
 /// Nothing really interesting here, it just provides memory for the rest of the crate.
@@ -1718,6 +1721,7 @@ impl<'a> Resolver<'a> {
             unused_macros: FxHashSet(),
             current_type_ascription: Vec::new(),
             injected_crate: None,
+            ignore_extern_prelude_feature: false,
         }
     }
 
@@ -1891,7 +1895,8 @@ impl<'a> Resolver<'a> {
         if !module.no_implicit_prelude {
             // `record_used` means that we don't try to load crates during speculative resolution
             if record_used && ns == TypeNS && self.extern_prelude.contains(&ident.name) {
-                if !self.session.features_untracked().extern_prelude {
+                if !self.session.features_untracked().extern_prelude &&
+                   !self.ignore_extern_prelude_feature {
                     feature_err(&self.session.parse_sess, "extern_prelude",
                                 ident.span, GateIssue::Language,
                                 "access to extern crates through prelude is experimental").emit();

src/librustdoc/clean/mod.rs

@@ -1103,7 +1103,7 @@ fn resolve(cx: &DocContext, path_str: &str, is_val: bool) -> Result<(Def, Option
             // early return and try looking for the trait
             let value = match result.def {
                 Def::Method(_) | Def::AssociatedConst(_) => true,
-                Def::AssociatedTy(_)  => false,
+                Def::AssociatedTy(_) => false,
                 Def::Variant(_) => return handle_variant(cx, result.def),
                 // not a trait item, just return what we found
                 _ => return Ok((result.def, None))

src/librustdoc/core.rs

@@ -250,10 +250,12 @@ pub fn run_core(search_paths: SearchPaths,
                                                         |_| Ok(()));
         let driver::InnerExpansionResult {
             mut hir_forest,
-            resolver,
+            mut resolver,
             ..
         } = abort_on_err(result, &sess);
 
+        resolver.ignore_extern_prelude_feature = true;
+
         // We need to hold on to the complete resolver, so we clone everything
         // for the analysis passes to use. Suboptimal, but necessary in the
         // current architecture.

src/libstd/lib.rs

@@ -239,6 +239,7 @@
 #![feature(allow_internal_unsafe)]
 #![feature(allow_internal_unstable)]
 #![feature(align_offset)]
+#![feature(arbitrary_self_types)]
 #![feature(array_error_internals)]
 #![feature(ascii_ctype)]
 #![feature(asm)]

src/libstd/panic.rs

@@ -15,11 +15,14 @@
 use any::Any;
 use cell::UnsafeCell;
 use fmt;
+use future::Future;
+use mem::PinMut;
 use ops::{Deref, DerefMut};
 use panicking;
 use ptr::{Unique, NonNull};
 use rc::Rc;
 use sync::{Arc, Mutex, RwLock, atomic};
+use task::{self, Poll};
 use thread::Result;
 
 #[stable(feature = "panic_hooks", since = "1.10.0")]
@@ -315,6 +318,21 @@ impl<T: fmt::Debug> fmt::Debug for AssertUnwindSafe<T> {
     }
 }
 
+#[unstable(feature = "futures_api", issue = "50547")]
+impl<'a, F: Future> Future for AssertUnwindSafe<F> {
+    type Output = F::Output;
+
+    fn poll(mut self: PinMut<Self>, cx: &mut task::Context) -> Poll<Self::Output> {
+        unsafe {
+            let pinned_field = PinMut::new_unchecked(
+                &mut PinMut::get_mut(self.reborrow()).0
+            );
+
+            pinned_field.poll(cx)
+        }
+    }
+}
+
 /// Invokes a closure, capturing the cause of an unwinding panic if one occurs.
 ///
 /// This function will return `Ok` with the closure's result if the closure

src/libsyntax/parse/parser.rs

@@ -760,7 +760,7 @@ impl<'a> Parser<'a> {
         err
     }
 
-    fn parse_ident(&mut self) -> PResult<'a, ast::Ident> {
+    pub fn parse_ident(&mut self) -> PResult<'a, ast::Ident> {
         self.parse_ident_common(true)
     }
 
@@ -1022,7 +1022,7 @@ impl<'a> Parser<'a> {
     /// Parse a sequence, including the closing delimiter. The function
     /// f must consume tokens until reaching the next separator or
     /// closing bracket.
-    crate fn parse_seq_to_end<T, F>(&mut self,
+    pub fn parse_seq_to_end<T, F>(&mut self,
                                   ket: &token::Token,
                                   sep: SeqSep,
                                   f: F)
@@ -1886,7 +1886,7 @@ impl<'a> Parser<'a> {
     /// `a::b::C::<D>` (with disambiguator)
     /// `Fn(Args)` (without disambiguator)
     /// `Fn::(Args)` (with disambiguator)
-    crate fn parse_path(&mut self, style: PathStyle) -> PResult<'a, ast::Path> {
+    pub fn parse_path(&mut self, style: PathStyle) -> PResult<'a, ast::Path> {
         self.parse_path_common(style, true)
     }