stabilise ?, attributes on stmts, deprecate Reflect

src/doc/reference.md

@@ -2472,8 +2472,7 @@ The currently implemented features of the reference compiler are:
 * - `default_type_parameter_fallback` - Allows type parameter defaults to
                                         influence type inference.
 
-* - `stmt_expr_attributes` - Allows attributes on expressions and
-                             non-item statements.
+* - `stmt_expr_attributes` - Allows attributes on expressions.
 
 * - `type_ascription` - Allows type ascription expressions `expr: Type`.
 

src/libcore/any.rs

@@ -73,7 +73,6 @@
 
 use fmt;
 use intrinsics;
-use marker::Reflect;
 
 ///////////////////////////////////////////////////////////////////////////////
 // Any trait
@@ -86,7 +85,7 @@ use marker::Reflect;
 ///
 /// [mod]: index.html
 #[stable(feature = "rust1", since = "1.0.0")]
-pub trait Any: Reflect + 'static {
+pub trait Any: 'static {
     /// Gets the `TypeId` of `self`.
     ///
     /// # Examples
@@ -112,7 +111,7 @@ pub trait Any: Reflect + 'static {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Reflect + 'static + ?Sized > Any for T {
+impl<T: 'static + ?Sized > Any for T {
     fn get_type_id(&self) -> TypeId { TypeId::of::<T>() }
 }
 
@@ -366,7 +365,7 @@ impl TypeId {
     /// }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn of<T: ?Sized + Reflect + 'static>() -> TypeId {
+    pub fn of<T: ?Sized + 'static>() -> TypeId {
         TypeId {
             t: unsafe { intrinsics::type_id::<T>() },
         }

src/libcore/lib.rs

@@ -89,7 +89,7 @@
 #![feature(specialization)]
 #![feature(staged_api)]
 #![feature(unboxed_closures)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(never_type)]
 #![feature(prelude_import)]
 

src/libcore/macros.rs

@@ -255,6 +255,9 @@ macro_rules! debug_assert_ne {
 /// Helper macro for reducing boilerplate code for matching `Result` together
 /// with converting downstream errors.
 ///
+/// Prefer using `?` syntax to `try!`. `?` is built in to the language and is
+/// more succinct than `try!`. It is the standard method for error propagation.
+///
 /// `try!` matches the given `Result`. In case of the `Ok` variant, the
 /// expression has the value of the wrapped value.
 ///

src/libcore/marker.rs

@@ -587,11 +587,14 @@ mod impls {
 #[unstable(feature = "reflect_marker",
            reason = "requires RFC and more experience",
            issue = "27749")]
+#[rustc_deprecated(since = "1.14.0", reason = "Specialization makes parametricity impossible")]
 #[rustc_on_unimplemented = "`{Self}` does not implement `Any`; \
                             ensure all type parameters are bounded by `Any`"]
 pub trait Reflect {}
 
 #[unstable(feature = "reflect_marker",
            reason = "requires RFC and more experience",
            issue = "27749")]
+#[rustc_deprecated(since = "1.14.0", reason = "Specialization makes parametricity impossible")]
+#[allow(deprecated)]
 impl Reflect for .. { }

src/libgraphviz/lib.rs

@@ -295,7 +295,7 @@
 #![cfg_attr(not(stage0), deny(warnings))]
 
 #![feature(str_escape)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 use self::LabelText::*;
 

src/librustc/diagnostics.rs

@@ -1327,30 +1327,6 @@ let x: i32 = "I am not a number!";
 //      |
 //    type `i32` assigned to variable `x`
 ```
-
-Another situation in which this occurs is when you attempt to use the `try!`
-macro inside a function that does not return a `Result<T, E>`:
-
-```compile_fail,E0308
-use std::fs::File;
-
-fn main() {
-    let mut f = try!(File::create("foo.txt"));
-}
-```
-
-This code gives an error like this:
-
-```text
-<std macros>:5:8: 6:42 error: mismatched types:
- expected `()`,
-     found `core::result::Result<_, _>`
- (expected (),
-     found enum `core::result::Result`) [E0308]
-```
-
-`try!` returns a `Result<T, E>`, and so the function must. But `main()` has
-`()` as its return type, hence the error.
 "##,
 
 E0309: r##"

src/librustc/lib.rs

@@ -40,7 +40,7 @@
 #![feature(rustc_private)]
 #![feature(slice_patterns)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![cfg_attr(test, feature(test))]
 
 extern crate arena;

src/librustc_back/lib.rs

@@ -37,7 +37,7 @@
 #![feature(rustc_private)]
 #![feature(staged_api)]
 #![feature(step_by)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![cfg_attr(test, feature(test, rand))]
 
 extern crate syntax;

src/librustc_borrowck/lib.rs

@@ -26,7 +26,7 @@
 #![feature(staged_api)]
 #![feature(associated_consts)]
 #![feature(nonzero)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #[macro_use] extern crate log;
 #[macro_use] extern crate syntax;
 extern crate syntax_pos;

src/librustc_const_eval/lib.rs

@@ -27,7 +27,7 @@
 #![feature(staged_api)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(slice_patterns)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 

src/librustc_const_math/lib.rs

@@ -25,7 +25,7 @@
 
 #![feature(rustc_private)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 #[macro_use] extern crate log;
 #[macro_use] extern crate syntax;

src/librustc_driver/lib.rs

@@ -31,7 +31,7 @@
 #![feature(rustc_private)]
 #![feature(set_stdio)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 extern crate arena;
 extern crate flate;

src/librustc_errors/lib.rs

@@ -21,7 +21,7 @@
 #![allow(unused_attributes)]
 #![feature(rustc_private)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(range_contains)]
 #![feature(libc)]
 #![feature(unicode)]

src/librustc_incremental/lib.rs

@@ -20,7 +20,7 @@
 #![cfg_attr(not(stage0), deny(warnings))]
 
 #![feature(dotdot_in_tuple_patterns)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(rustc_private)]
 #![feature(staged_api)]
 #![feature(rand)]

src/librustc_metadata/lib.rs

@@ -23,7 +23,7 @@
 #![feature(dotdot_in_tuple_patterns)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_lib)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(quote)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(rustc_private)]

src/librustc_mir/lib.rs

@@ -26,7 +26,7 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 #![feature(rustc_diagnostic_macros)]
 #![feature(rustc_private)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 #[macro_use] extern crate log;
 extern crate graphviz as dot;

src/librustc_trans/lib.rs

@@ -36,7 +36,7 @@
 #![feature(slice_patterns)]
 #![feature(staged_api)]
 #![feature(unicode)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 use rustc::dep_graph::WorkProduct;
 

src/librustc_typeck/lib.rs

@@ -82,7 +82,7 @@ This API is completely unstable and subject to change.
 #![feature(rustc_diagnostic_macros)]
 #![feature(rustc_private)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 #[macro_use] extern crate log;
 #[macro_use] extern crate syntax;

src/librustdoc/lib.rs

@@ -28,7 +28,7 @@
 #![feature(staged_api)]
 #![feature(test)]
 #![feature(unicode)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 extern crate arena;
 extern crate getopts;

src/libserialize/lib.rs

@@ -35,7 +35,7 @@ Core encoding and decoding interfaces.
 #![feature(specialization)]
 #![feature(staged_api)]
 #![feature(unicode)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![cfg_attr(test, feature(test))]
 
 // test harness access

src/libstd/error.rs

@@ -55,15 +55,14 @@ use any::TypeId;
 use cell;
 use char;
 use fmt::{self, Debug, Display};
-use marker::Reflect;
 use mem::transmute;
 use num;
 use str;
 use string;
 
 /// Base functionality for all errors in Rust.
 #[stable(feature = "rust1", since = "1.0.0")]
-pub trait Error: Debug + Display + Reflect {
+pub trait Error: Debug + Display {
     /// A short description of the error.
     ///
     /// The description should not contain newlines or sentence-ending

src/libstd/io/buffered.rs

@@ -12,7 +12,6 @@
 
 use io::prelude::*;
 
-use marker::Reflect;
 use cmp;
 use error;
 use fmt;
@@ -578,7 +577,7 @@ impl<W> From<IntoInnerError<W>> for Error {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<W: Reflect + Send + fmt::Debug> error::Error for IntoInnerError<W> {
+impl<W: Send + fmt::Debug> error::Error for IntoInnerError<W> {
     fn description(&self) -> &str {
         error::Error::description(self.error())
     }

src/libstd/lib.rs

@@ -255,10 +255,9 @@
 #![feature(panic_unwind)]
 #![feature(placement_in_syntax)]
 #![feature(prelude_import)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(rand)]
 #![feature(raw)]
-#![feature(reflect_marker)]
 #![feature(repr_simd)]
 #![feature(rustc_attrs)]
 #![feature(shared)]

src/libstd/sync/mpsc/mod.rs

@@ -270,7 +270,6 @@ use error;
 use fmt;
 use mem;
 use cell::UnsafeCell;
-use marker::Reflect;
 use time::{Duration, Instant};
 
 #[unstable(feature = "mpsc_select", issue = "27800")]
@@ -1163,7 +1162,7 @@ impl<T> fmt::Display for SendError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> error::Error for SendError<T> {
+impl<T: Send> error::Error for SendError<T> {
     fn description(&self) -> &str {
         "sending on a closed channel"
     }
@@ -1198,7 +1197,7 @@ impl<T> fmt::Display for TrySendError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> error::Error for TrySendError<T> {
+impl<T: Send> error::Error for TrySendError<T> {
 
     fn description(&self) -> &str {
         match *self {

src/libstd/sys/common/poison.rs

@@ -10,7 +10,6 @@
 
 use error::{Error};
 use fmt;
-use marker::Reflect;
 use sync::atomic::{AtomicBool, Ordering};
 use thread;
 
@@ -117,7 +116,7 @@ impl<T> fmt::Display for PoisonError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Reflect> Error for PoisonError<T> {
+impl<T> Error for PoisonError<T> {
     fn description(&self) -> &str {
         "poisoned lock: another task failed inside"
     }
@@ -174,7 +173,7 @@ impl<T> fmt::Display for TryLockError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Reflect> Error for TryLockError<T> {
+impl<T> Error for TryLockError<T> {
     fn description(&self) -> &str {
         match *self {
             TryLockError::Poisoned(ref p) => p.description(),

src/libsyntax/config.rs

@@ -153,7 +153,7 @@ impl<'a> StripUnconfigured<'a> {
     }
 
     // Visit attributes on expression and statements (but not attributes on items in blocks).
-    fn visit_stmt_or_expr_attrs(&mut self, attrs: &[ast::Attribute]) {
+    fn visit_expr_attrs(&mut self, attrs: &[ast::Attribute]) {
         // flag the offending attributes
         for attr in attrs.iter() {
             if !self.features.map(|features| features.stmt_expr_attributes).unwrap_or(true) {
@@ -227,7 +227,7 @@ impl<'a> StripUnconfigured<'a> {
     }
 
     pub fn configure_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
-        self.visit_stmt_or_expr_attrs(expr.attrs());
+        self.visit_expr_attrs(expr.attrs());
 
         // If an expr is valid to cfg away it will have been removed by the
         // outer stmt or expression folder before descending in here.
@@ -245,7 +245,6 @@ impl<'a> StripUnconfigured<'a> {
     }
 
     pub fn configure_stmt(&mut self, stmt: ast::Stmt) -> Option<ast::Stmt> {
-        self.visit_stmt_or_expr_attrs(stmt.attrs());
         self.configure(stmt)
     }
 }

src/libsyntax/feature_gate.rs

@@ -253,9 +253,6 @@ declare_features! (
     // a...b and ...b
     (active, inclusive_range_syntax, "1.7.0", Some(28237)),
 
-    // `expr?`
-    (active, question_mark, "1.9.0", Some(31436)),
-
     // impl specialization (RFC 1210)
     (active, specialization, "1.7.0", Some(31844)),
 
@@ -348,6 +345,8 @@ declare_features! (
     (accepted, while_let, "1.0.0", None),
     // Allows `#[deprecated]` attribute
     (accepted, deprecated, "1.9.0", Some(29935)),
+    // `expr?`
+    (accepted, question_mark, "1.14.0", Some(31436)),
 );
 // (changing above list without updating src/doc/reference.md makes @cmr sad)
 
@@ -1072,9 +1071,6 @@ impl<'a> Visitor for PostExpansionVisitor<'a> {
                                   e.span,
                                   "inclusive range syntax is experimental");
             }
-            ast::ExprKind::Try(..) => {
-                gate_feature_post!(&self, question_mark, e.span, "the `?` operator is not stable");
-            }
             ast::ExprKind::InPlace(..) => {
                 gate_feature_post!(&self, placement_in_syntax, e.span, EXPLAIN_PLACEMENT_IN);
             }

src/libsyntax/lib.rs

@@ -31,7 +31,7 @@
 #![feature(staged_api)]
 #![feature(str_escape)]
 #![feature(unicode)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(rustc_diagnostic_macros)]
 #![feature(specialization)]
 

src/libsyntax_pos/lib.rs

@@ -27,7 +27,7 @@
 #![allow(unused_attributes)]
 #![feature(rustc_private)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(specialization)]
 
 use std::cell::{Cell, RefCell};

src/libterm/lib.rs

@@ -59,7 +59,7 @@
 #![cfg_attr(windows, feature(libc))]
 // Handle rustfmt skips
 #![feature(custom_attribute)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![allow(unused_attributes)]
 
 use std::io::prelude::*;

src/libtest/lib.rs

@@ -38,7 +38,7 @@
 #![feature(rustc_private)]
 #![feature(set_stdio)]
 #![feature(staged_api)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 #![feature(panic_unwind)]
 
 extern crate getopts;

src/test/compile-fail/issue-32709.rs

@@ -8,12 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(question_mark)]
-
 // Make sure that the span of try shorthand does not include the trailing
 // semicolon;
 fn a() -> Result<i32, ()> {
-    Err(5)?; //~ ERROR 16:5: 16:12
+    Err(5)?; //~ ERROR 14:5: 14:12
     Ok(1)
 }
 

src/test/compile-fail/issue-33876.rs

@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(reflect_marker)]
-
-use std::marker::Reflect;
 use std::any::Any;
 
 struct Foo;

src/test/compile-fail/mir-dataflow/def-inits-1.rs

@@ -11,7 +11,6 @@
 // General test of maybe_uninits state computed by MIR dataflow.
 
 #![feature(rustc_attrs)]
-#![feature(stmt_expr_attributes)]
 
 use std::intrinsics::rustc_peek;
 use std::mem::{drop, replace};

src/test/compile-fail/mir-dataflow/inits-1.rs

@@ -11,7 +11,6 @@
 // General test of maybe_inits state computed by MIR dataflow.
 
 #![feature(rustc_attrs)]
-#![feature(stmt_expr_attributes)]
 
 use std::intrinsics::rustc_peek;
 use std::mem::{drop, replace};

src/test/compile-fail/mir-dataflow/uninits-1.rs

@@ -11,7 +11,6 @@
 // General test of maybe_uninits state computed by MIR dataflow.
 
 #![feature(rustc_attrs)]
-#![feature(stmt_expr_attributes)]
 
 use std::intrinsics::rustc_peek;
 use std::mem::{drop, replace};

src/test/compile-fail/mir-dataflow/uninits-2.rs

@@ -11,7 +11,6 @@
 // General test of maybe_uninits state computed by MIR dataflow.
 
 #![feature(rustc_attrs)]
-#![feature(stmt_expr_attributes)]
 
 use std::intrinsics::rustc_peek;
 use std::mem::{drop, replace};

src/test/compile-fail/stmt_expr_attrs_no_feature.rs

@@ -21,15 +21,15 @@ fn main() {
     #[attr]
     fn a() {}
 
-    #[attr] //~ ERROR 15701
+    #[attr]
     {
 
     }
 
-    #[attr] //~ ERROR 15701
+    #[attr]
     5;
 
-    #[attr] //~ ERROR 15701
+    #[attr]
     stmt_mac!();
 }
 
@@ -43,7 +43,7 @@ fn c() {
 
 #[cfg(not(unset))]
 fn j() {
-    #[attr] //~ ERROR 15701
+    #[attr]
     5;
 }
 
@@ -55,7 +55,7 @@ fn d() {
 
 #[cfg_attr(not(unset), cfg(not(unset)))]
 fn i() {
-    #[attr] //~ ERROR 15701
+    #[attr]
     8;
 }
 
@@ -64,7 +64,7 @@ fn i() {
 macro_rules! item_mac {
     ($e:ident) => {
         fn $e() {
-            #[attr] //~ ERROR 15701
+            #[attr]
             42;
 
             #[cfg(unset)]
@@ -75,7 +75,7 @@ macro_rules! item_mac {
 
             #[cfg(not(unset))]
             fn k() {
-                #[attr] //~ ERROR 15701
+                #[attr]
                 5;
             }
 
@@ -87,7 +87,7 @@ macro_rules! item_mac {
 
             #[cfg_attr(not(unset), cfg(not(unset)))]
             fn h() {
-                #[attr] //~ ERROR 15701
+                #[attr]
                 8;
             }
 

src/test/run-pass/const-negation.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(stmt_expr_attributes)]
-
 #[deny(const_err)]
 
 fn main() {

src/test/run-pass/enum-discrim-autosizing.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(stmt_expr_attributes)]
-
 use std::mem::size_of;
 
 enum Ei8 {

src/test/run-pass/ifmt.rs

@@ -14,7 +14,6 @@
 #![allow(unused_must_use)]
 #![allow(unused_features)]
 #![feature(box_syntax)]
-#![feature(question_mark)]
 
 use std::fmt::{self, Write};
 use std::usize;

src/test/run-pass/impl-trait/example-st.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(conservative_impl_trait, question_mark)]
+#![feature(conservative_impl_trait)]
 
 struct State;
 type Error = ();

src/test/run-pass/issue-17121.rs

@@ -10,8 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(question_mark)]
-
 use std::fs::File;
 use std::io::{self, BufReader, Read};
 

src/test/run-pass/issue-19404.rs

@@ -8,17 +8,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(reflect_marker)]
-
 use std::any::TypeId;
-use std::marker::Reflect;
 use std::rc::Rc;
 
 type Fp<T> = Rc<T>;
 
 struct Engine;
 
-trait Component: 'static + Reflect {}
+trait Component: 'static {}
 impl Component for Engine {}
 
 trait Env {

src/test/run-pass/issue-20797.rs

@@ -10,8 +10,6 @@
 
 // Regression test for #20797.
 
-#![feature(question_mark)]
-
 use std::default::Default;
 use std::io;
 use std::fs;

src/test/run-pass/issue-21400.rs

@@ -11,8 +11,6 @@
 // Regression test for #21400 which itself was extracted from
 // stackoverflow.com/questions/28031155/is-my-borrow-checker-drunk/28031580
 
-#![feature(question_mark)]
-
 fn main() {
     let mut t = Test;
     assert_eq!(t.method1("one"), Ok(1));

src/test/run-pass/issue-8460.rs

@@ -11,7 +11,7 @@
 // ignore-emscripten no threads support
 // ignore-pretty : (#23623) problems when  ending with // comments
 
-#![feature(rustc_attrs, stmt_expr_attributes, zero_one)]
+#![feature(rustc_attrs, zero_one)]
 
 use std::num::Zero;
 use std::thread;

src/test/run-pass/try-operator-hygiene.rs

@@ -18,8 +18,6 @@
 // This test verifies that the expansion is hygienic, i.e. it's not affected by other `val` and
 // `err` bindings that may be in scope.
 
-#![feature(question_mark)]
-
 use std::num::ParseIntError;
 
 fn main() {

src/test/run-pass/try-operator.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(question_mark)]
-
 use std::fs::File;
 use std::io::{Read, self};
 use std::num::ParseIntError;

src/tools/compiletest/src/main.rs

@@ -13,7 +13,6 @@
 #![feature(box_syntax)]
 #![feature(rustc_private)]
 #![feature(test)]
-#![feature(question_mark)]
 #![feature(libc)]
 
 #![deny(warnings)]

src/tools/error_index_generator/main.rs

@@ -9,7 +9,6 @@
 // except according to those terms.
 
 #![feature(rustc_private, rustdoc)]
-#![feature(question_mark)]
 
 extern crate syntax;
 extern crate rustdoc;

src/tools/linkchecker/main.rs

@@ -24,8 +24,6 @@
 //! A few whitelisted exceptions are allowed as there's known bugs in rustdoc,
 //! but this should catch the majority of "broken link" cases.
 
-#![feature(question_mark)]
-
 extern crate url;
 
 use std::env;

src/tools/rustbook/main.rs

@@ -12,7 +12,6 @@
 
 #![feature(rustc_private)]
 #![feature(rustdoc)]
-#![feature(question_mark)]
 
 extern crate rustdoc;
 extern crate rustc_back;