Auto merge of #35906 - jseyfried:local_prelude, r=eddyb

Use `#[prelude_import]` in `libcore` and `libstd`

r? @eddyb

src/libcollections/binary_heap.rs

@@ -151,7 +151,7 @@
 #![allow(missing_docs)]
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use core::ops::{Drop, Deref, DerefMut};
+use core::ops::{Deref, DerefMut};
 use core::iter::{FromIterator, FusedIterator};
 use core::mem::swap;
 use core::mem::size_of;

src/libcollections/borrow.rs

@@ -12,14 +12,9 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use core::clone::Clone;
-use core::cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd};
-use core::convert::AsRef;
-use core::default::Default;
+use core::cmp::Ordering;
 use core::hash::{Hash, Hasher};
-use core::marker::Sized;
 use core::ops::Deref;
-use core::option::Option;
 
 use fmt;
 

src/libcollections/linked_list.rs

@@ -1159,9 +1159,6 @@ unsafe impl<'a, T: Sync> Sync for IterMut<'a, T> {}
 
 #[cfg(test)]
 mod tests {
-    use std::clone::Clone;
-    use std::iter::{Iterator, IntoIterator, Extend};
-    use std::option::Option::{self, Some, None};
     use std::__rand::{thread_rng, Rng};
     use std::thread;
     use std::vec::Vec;
@@ -1319,7 +1316,6 @@ mod tests {
 
     #[test]
     fn test_26021() {
-        use std::iter::ExactSizeIterator;
         // There was a bug in split_off that failed to null out the RHS's head's prev ptr.
         // This caused the RHS's dtor to walk up into the LHS at drop and delete all of
         // its nodes.

src/libcollections/range.rs

@@ -14,7 +14,6 @@
 
 //! Range syntax.
 
-use core::option::Option::{self, None, Some};
 use core::ops::{RangeFull, Range, RangeTo, RangeFrom};
 
 /// **RangeArgument** is implemented by Rust's built-in range types, produced

src/libcollections/vec_deque.rs

@@ -2332,9 +2332,6 @@ impl<T> From<VecDeque<T>> for Vec<T> {
 
 #[cfg(test)]
 mod tests {
-    use core::iter::Iterator;
-    use core::option::Option::Some;
-
     use test;
 
     use super::VecDeque;

src/libcore/any.rs

@@ -72,12 +72,10 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use fmt;
-use marker::Send;
 use mem::transmute;
-use option::Option::{self, Some, None};
 use raw::TraitObject;
 use intrinsics;
-use marker::{Reflect, Sized};
+use marker::Reflect;
 
 ///////////////////////////////////////////////////////////////////////////////
 // Any trait

src/libcore/array.rs

@@ -20,16 +20,11 @@
             issue = "27778")]
 
 use borrow::{Borrow, BorrowMut};
-use clone::Clone;
-use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
-use convert::{AsRef, AsMut};
-use default::Default;
+use cmp::Ordering;
 use fmt;
 use hash::{Hash, self};
-use iter::IntoIterator;
-use marker::{Copy, Sized, Unsize};
-use option::Option;
-use slice::{Iter, IterMut, SliceExt};
+use marker::Unsize;
+use slice::{Iter, IterMut};
 
 /// Utility trait implemented only on arrays of fixed size
 ///

src/libcore/borrow.rs

@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-
 /// A trait for borrowing data.
 ///
 /// In general, there may be several ways to "borrow" a piece of data.  The

src/libcore/cell.rs

@@ -144,17 +144,10 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
-use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
-use convert::From;
-use default::Default;
+use cmp::Ordering;
 use fmt::{self, Debug, Display};
-use marker::{Copy, PhantomData, Send, Sync, Sized, Unsize};
-use ops::{Deref, DerefMut, Drop, FnOnce, CoerceUnsized};
-use option::Option;
-use option::Option::{None, Some};
-use result::Result;
-use result::Result::{Ok, Err};
+use marker::{PhantomData, Unsize};
+use ops::{Deref, DerefMut, CoerceUnsized};
 
 /// A mutable memory location that admits only `Copy` data.
 ///

src/libcore/char.rs

@@ -15,8 +15,6 @@
 #![allow(non_snake_case)]
 #![stable(feature = "core_char", since = "1.2.0")]
 
-use prelude::v1::*;
-
 use char_private::is_printable;
 use iter::FusedIterator;
 use mem::transmute;

src/libcore/char_private.rs

@@ -11,8 +11,6 @@
 // NOTE: The following code was generated by "src/etc/char_private.py",
 //       do not edit directly!
 
-use slice::SliceExt;
-
 fn check(x: u16, singletons: &[u16], normal: &[u16]) -> bool {
     for &s in singletons {
         if x == s {

src/libcore/clone.rs

@@ -44,8 +44,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-
 /// A common trait for the ability to explicitly duplicate an object.
 ///
 /// Differs from `Copy` in that `Copy` is implicit and extremely inexpensive, while

src/libcore/cmp.rs

@@ -34,9 +34,6 @@
 
 use self::Ordering::*;
 
-use marker::Sized;
-use option::Option::{self, Some};
-
 /// Trait for equality comparisons which are [partial equivalence
 /// relations](http://en.wikipedia.org/wiki/Partial_equivalence_relation).
 ///
@@ -571,11 +568,7 @@ pub fn max<T: Ord>(v1: T, v2: T) -> T {
 
 // Implementation of PartialEq, Eq, PartialOrd and Ord for primitive types
 mod impls {
-    use cmp::{PartialOrd, Ord, PartialEq, Eq, Ordering};
-    use cmp::Ordering::{Less, Greater, Equal};
-    use marker::Sized;
-    use option::Option;
-    use option::Option::{Some, None};
+    use cmp::Ordering::{self, Less, Greater, Equal};
 
     macro_rules! partial_eq_impl {
         ($($t:ty)*) => ($(

src/libcore/convert.rs

@@ -40,9 +40,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-use result::Result;
-
 /// A cheap, reference-to-reference conversion.
 ///
 /// `AsRef` is very similar to, but different than, `Borrow`. See

src/libcore/default.rs

@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
-
 /// A trait for giving a type a useful default value.
 ///
 /// Sometimes, you want to fall back to some kind of default value, and

src/libcore/fmt/builders.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
 use fmt::{self, FlagV1};
 
 struct PadAdapter<'a, 'b: 'a> {

src/libcore/fmt/mod.rs

@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::v1::*;
-
 use cell::{UnsafeCell, Cell, RefCell, Ref, RefMut, BorrowState};
 use marker::PhantomData;
 use mem;
@@ -905,8 +903,6 @@ impl<'a> Formatter<'a> {
                         prefix: &str,
                         buf: &str)
                         -> Result {
-        use char::CharExt;
-
         let mut width = buf.len();
 
         let mut sign = None;
@@ -1020,7 +1016,6 @@ impl<'a> Formatter<'a> {
                        f: F) -> Result
         where F: FnOnce(&mut Formatter) -> Result,
     {
-        use char::CharExt;
         let align = match self.align {
             rt::v1::Alignment::Unknown => default,
             _ => self.align

src/libcore/fmt/num.rs

@@ -14,8 +14,6 @@
 
 // FIXME: #6220 Implement floating point formatting
 
-use prelude::v1::*;
-
 use fmt;
 use num::Zero;
 use ops::{Div, Rem, Sub};

src/libcore/hash/mod.rs

@@ -71,8 +71,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::v1::*;
-
 use fmt;
 use marker;
 use mem;
@@ -288,8 +286,6 @@ impl<H> Default for BuildHasherDefault<H> {
 //////////////////////////////////////////////////////////////////////////////
 
 mod impls {
-    use prelude::v1::*;
-
     use mem;
     use slice;
     use super::*;

src/libcore/hash/sip.rs

@@ -10,8 +10,6 @@
 
 //! An implementation of SipHash.
 
-use prelude::v1::*;
-
 use marker::PhantomData;
 use ptr;
 

src/libcore/intrinsics.rs

@@ -46,8 +46,6 @@
             issue = "0")]
 #![allow(missing_docs)]
 
-use marker::Sized;
-
 extern "rust-intrinsic" {
 
     // NB: These intrinsics take raw pointers because they mutate aliased

src/libcore/iter/iterator.rs

@@ -8,19 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use clone::Clone;
-use cmp::{Ord, PartialOrd, PartialEq, Ordering};
-use default::Default;
-use ops::FnMut;
-use option::Option::{self, Some, None};
-use marker::Sized;
+use cmp::Ordering;
 
 use super::{Chain, Cycle, Cloned, Enumerate, Filter, FilterMap, FlatMap, Fuse};
 use super::{Inspect, Map, Peekable, Scan, Skip, SkipWhile, Take, TakeWhile, Rev};
 use super::{Zip, Sum, Product};
-use super::ChainState;
-use super::{DoubleEndedIterator, ExactSizeIterator, Extend, FromIterator};
-use super::{IntoIterator, ZipImpl};
+use super::{ChainState, FromIterator, ZipImpl};
 
 fn _assert_is_object_safe(_: &Iterator<Item=()>) {}
 

src/libcore/iter/mod.rs

@@ -299,13 +299,9 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
 use cmp;
-use default::Default;
 use fmt;
 use iter_private::TrustedRandomAccess;
-use ops::FnMut;
-use option::Option::{self, Some, None};
 use usize;
 
 #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/iter/range.rs

@@ -8,15 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use clone::Clone;
-use cmp::PartialOrd;
 use mem;
 use ops::{self, Add, Sub};
-use option::Option::{self, Some, None};
-use marker::Sized;
 use usize;
 
-use super::{DoubleEndedIterator, ExactSizeIterator, Iterator, FusedIterator};
+use super::FusedIterator;
 
 /// Objects that can be stepped over in both directions.
 ///

src/libcore/iter/sources.rs

@@ -8,14 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use clone::Clone;
-use default::Default;
 use fmt;
 use marker;
-use option::Option::{self, Some, None};
 use usize;
 
-use super::{DoubleEndedIterator, IntoIterator, Iterator, ExactSizeIterator, FusedIterator};
+use super::FusedIterator;
 
 /// An iterator that repeats an element endlessly.
 ///

src/libcore/iter/traits.rs

@@ -8,11 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use option::Option::{self, Some};
-use marker::Sized;
-
-use super::Iterator;
-
 /// Conversion from an `Iterator`.
 ///
 /// By implementing `FromIterator` for a type, you define how it will be

src/libcore/iter_private.rs

@@ -9,8 +9,6 @@
 // except according to those terms.
 
 
-use iter::ExactSizeIterator;
-
 /// An iterator whose items are random accessible efficiently
 ///
 /// # Safety

src/libcore/lib.rs

@@ -91,6 +91,11 @@
 #![feature(unboxed_closures)]
 #![feature(question_mark)]
 #![feature(never_type)]
+#![feature(prelude_import)]
+
+#[prelude_import]
+#[allow(unused)]
+use prelude::v1::*;
 
 #[macro_use]
 mod macros;

src/libcore/marker.rs

@@ -16,10 +16,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
 use cmp;
-use default::Default;
-use option::Option;
 use hash::Hash;
 use hash::Hasher;
 
@@ -414,8 +411,6 @@ pub struct PhantomData<T:?Sized>;
 impls! { PhantomData }
 
 mod impls {
-    use super::{Send, Sync, Sized};
-
     #[stable(feature = "rust1", since = "1.0.0")]
     unsafe impl<'a, T: Sync + ?Sized> Send for &'a T {}
     #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/mem.rs

@@ -15,7 +15,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use marker::Sized;
 use intrinsics;
 use ptr;
 

src/libcore/nonzero.rs

@@ -13,7 +13,6 @@
             reason = "needs an RFC to flesh out the design",
             issue = "27730")]
 
-use marker::Sized;
 use ops::{CoerceUnsized, Deref};
 
 /// Unsafe trait to indicate what types are usable with the NonZero struct

src/libcore/num/bignum.rs

@@ -27,8 +27,6 @@
             issue = "0")]
 #![macro_use]
 
-use prelude::v1::*;
-
 use mem;
 use intrinsics;
 
@@ -494,6 +492,5 @@ define_bignum!(Big32x40: type=Digit32, n=40);
 // this one is used for testing only.
 #[doc(hidden)]
 pub mod tests {
-    use prelude::v1::*;
     define_bignum!(Big8x3: type=u8, n=3);
 }

src/libcore/num/dec2flt/algorithm.rs

@@ -10,7 +10,6 @@
 
 //! The various algorithms from the paper.
 
-use prelude::v1::*;
 use cmp::min;
 use cmp::Ordering::{Less, Equal, Greater};
 use num::diy_float::Fp;
@@ -47,7 +46,6 @@ mod fpu_precision {
 #[cfg(all(target_arch="x86", not(target_feature="sse2")))]
 mod fpu_precision {
     use mem::size_of;
-    use ops::Drop;
 
     /// A structure used to preserve the original value of the FPU control word, so that it can be
     /// restored when the structure is dropped.

src/libcore/num/dec2flt/mod.rs

@@ -92,7 +92,6 @@
             reason = "internal routines only exposed for testing",
             issue = "0")]
 
-use prelude::v1::*;
 use fmt;
 use str::FromStr;
 

src/libcore/num/dec2flt/num.rs

@@ -12,7 +12,6 @@
 
 // FIXME This module's name is a bit unfortunate, since other modules also import `core::num`.
 
-use prelude::v1::*;
 use cmp::Ordering::{self, Less, Equal, Greater};
 
 pub use num::bignum::Big32x40 as Big;

src/libcore/num/dec2flt/parse.rs

@@ -20,7 +20,6 @@
 //! modules rely on to not panic (or overflow) in turn.
 //! To make matters worse, all that happens in a single pass over the input.
 //! So, be careful when modifying anything, and double-check with the other modules.
-use prelude::v1::*;
 use super::num;
 use self::ParseResult::{Valid, ShortcutToInf, ShortcutToZero, Invalid};
 

src/libcore/num/dec2flt/rawfp.rs

@@ -27,7 +27,6 @@
 //! Many functions in this module only handle normal numbers. The dec2flt routines conservatively
 //! take the universally-correct slow path (Algorithm M) for very small and very large numbers.
 //! That algorithm needs only next_float() which does handle subnormals and zeros.
-use prelude::v1::*;
 use u32;
 use cmp::Ordering::{Less, Equal, Greater};
 use ops::{Mul, Div, Neg};

src/libcore/num/flt2dec/decoder.rs

@@ -10,8 +10,6 @@
 
 //! Decodes a floating-point value into individual parts and error ranges.
 
-use prelude::v1::*;
-
 use {f32, f64};
 use num::FpCategory;
 use num::dec2flt::rawfp::RawFloat;

src/libcore/num/flt2dec/mod.rs

@@ -130,7 +130,6 @@ functions.
             reason = "internal routines only exposed for testing",
             issue = "0")]
 
-use prelude::v1::*;
 use i16;
 pub use self::decoder::{decode, DecodableFloat, FullDecoded, Decoded};
 

src/libcore/num/flt2dec/strategy/dragon.rs

@@ -15,8 +15,6 @@ Almost direct (but slightly optimized) Rust translation of Figure 3 of [1].
     quickly and accurately. SIGPLAN Not. 31, 5 (May. 1996), 108-116.
 */
 
-use prelude::v1::*;
-
 use cmp::Ordering;
 
 use num::flt2dec::{Decoded, MAX_SIG_DIGITS, round_up};

src/libcore/num/flt2dec/strategy/grisu.rs

@@ -16,8 +16,6 @@ Rust adaptation of Grisu3 algorithm described in [1]. It uses about
     accurately with integers. SIGPLAN Not. 45, 6 (June 2010), 233-243.
 */
 
-use prelude::v1::*;
-
 use num::diy_float::Fp;
 use num::flt2dec::{Decoded, MAX_SIG_DIGITS, round_up};
 

src/libcore/num/mod.rs

@@ -12,17 +12,11 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use char::CharExt;
-use cmp::PartialOrd;
-use convert::{From, TryFrom};
+use convert::TryFrom;
 use fmt;
 use intrinsics;
-use marker::{Copy, Sized};
 use mem::size_of;
-use option::Option::{self, Some, None};
-use result::Result::{self, Ok, Err};
-use str::{FromStr, StrExt};
-use slice::SliceExt;
+use str::FromStr;
 
 /// Provides intentionally-wrapped arithmetic on `T`.
 ///

src/libcore/ops.rs

@@ -71,10 +71,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use cmp::PartialOrd;
 use fmt;
-use marker::{Sized, Unsize};
-use result::Result::{self, Ok, Err};
+use marker::Unsize;
 
 /// The `Drop` trait is used to run some code when a value goes out of scope.
 /// This is sometimes called a 'destructor'.
@@ -2208,9 +2206,6 @@ pub trait FnOnce<Args> {
 }
 
 mod impls {
-    use marker::Sized;
-    use super::{Fn, FnMut, FnOnce};
-
     #[stable(feature = "rust1", since = "1.0.0")]
     impl<'a,A,F:?Sized> Fn<A> for &'a F
         where F : Fn<A>

src/libcore/option.rs

@@ -139,17 +139,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use self::Option::*;
-
-use clone::Clone;
-use convert::From;
-use default::Default;
-use iter::{Iterator, FromIterator, IntoIterator, ExactSizeIterator, DoubleEndedIterator};
-use iter::FusedIterator;
+use iter::{FromIterator, FusedIterator};
 use mem;
-use ops::FnOnce;
-use result::Result::{Ok, Err};
-use result::Result;
 
 // Note that this is not a lang item per se, but it has a hidden dependency on
 // `Iterator`, which is one. The compiler assumes that the `next` method of

src/libcore/ptr.rs

@@ -16,17 +16,14 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use clone::Clone;
 use intrinsics;
 use ops::{CoerceUnsized, Deref};
 use fmt;
 use hash;
-use option::Option::{self, Some, None};
-use marker::{Copy, PhantomData, Send, Sized, Sync, Unsize};
+use marker::{PhantomData, Unsize};
 use mem;
 use nonzero::NonZero;
 
-use cmp::{PartialEq, Eq, Ord, PartialOrd};
 use cmp::Ordering::{self, Less, Equal, Greater};
 
 // FIXME #19649: intrinsic docs don't render, so these have no docs :(

src/libcore/result.rs

@@ -236,14 +236,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use self::Result::{Ok, Err};
-
-use clone::Clone;
 use fmt;
-use iter::{Iterator, DoubleEndedIterator, FromIterator, ExactSizeIterator, IntoIterator};
-use iter::FusedIterator;
-use ops::FnOnce;
-use option::Option::{self, None, Some};
+use iter::{FromIterator, FusedIterator};
 
 /// `Result` is a type that represents either success (`Ok`) or failure (`Err`).
 ///

src/libcore/slice.rs

@@ -33,24 +33,15 @@
 // * The `raw` and `bytes` submodules.
 // * Boilerplate trait implementations.
 
-use clone::Clone;
-use cmp::{Ordering, PartialEq, PartialOrd, Eq, Ord};
-use cmp::Ordering::{Less, Equal, Greater};
+use cmp::Ordering::{self, Less, Equal, Greater};
 use cmp;
-use convert::AsRef;
-use default::Default;
 use fmt;
 use intrinsics::assume;
 use iter::*;
-use ops::{FnMut, self};
-use ops::RangeFull;
-use option::Option;
-use option::Option::{None, Some};
-use result::Result;
-use result::Result::{Ok, Err};
+use ops::{self, RangeFull};
 use ptr;
 use mem;
-use marker::{Copy, Send, Sync, self};
+use marker;
 use iter_private::TrustedRandomAccess;
 
 #[repr(C)]

src/libcore/str/mod.rs

@@ -18,18 +18,10 @@ use self::pattern::Pattern;
 use self::pattern::{Searcher, ReverseSearcher, DoubleEndedSearcher};
 
 use char;
-use clone::Clone;
-use convert::AsRef;
-use default::Default;
 use fmt;
-use iter::ExactSizeIterator;
-use iter::{Map, Cloned, Iterator, DoubleEndedIterator, FusedIterator};
-use marker::Sized;
+use iter::{Map, Cloned, FusedIterator};
 use mem;
-use ops::{Fn, FnMut, FnOnce};
-use option::Option::{self, None, Some};
-use result::Result::{self, Ok, Err};
-use slice::{self, SliceExt};
+use slice;
 
 pub mod pattern;
 
@@ -1338,11 +1330,9 @@ Section: Trait implementations
 */
 
 mod traits {
-    use cmp::{Ord, Ordering, PartialEq, PartialOrd, Eq};
-    use option::Option;
-    use option::Option::Some;
+    use cmp::Ordering;
     use ops;
-    use str::{StrExt, eq_slice};
+    use str::eq_slice;
 
     #[stable(feature = "rust1", since = "1.0.0")]
     impl Ord for str {

src/libcore/str/pattern.rs

@@ -17,8 +17,6 @@
             reason = "API not fully fleshed out and ready to be stabilized",
             issue = "27721")]
 
-use prelude::v1::*;
-
 use cmp;
 use fmt;
 use usize;

src/libcore/sync/atomic.rs

@@ -79,14 +79,8 @@
 
 use self::Ordering::*;
 
-use marker::{Send, Sync};
-
 use intrinsics;
 use cell::UnsafeCell;
-
-use result::Result::{self, Ok, Err};
-
-use default::Default;
 use fmt;
 
 /// A boolean type which can be safely shared between threads.

src/libcore/tuple.rs

@@ -10,12 +10,8 @@
 
 // See src/libstd/primitive_docs.rs for documentation.
 
-use clone::Clone;
 use cmp::*;
 use cmp::Ordering::*;
-use default::Default;
-use option::Option;
-use option::Option::Some;
 
 // FIXME(#19630) Remove this work-around
 macro_rules! e {

src/libstd/ascii.rs

@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::v1::*;
-
 use mem;
 use ops::Range;
 use iter::FusedIterator;
@@ -454,7 +452,6 @@ static ASCII_UPPERCASE_MAP: [u8; 256] = [
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use super::*;
     use char::from_u32;
 

src/libstd/collections/hash/map.rs

@@ -2059,8 +2059,6 @@ fn assert_covariance() {
 
 #[cfg(test)]
 mod test_map {
-    use prelude::v1::*;
-
     use super::HashMap;
     use super::Entry::{Occupied, Vacant};
     use cell::RefCell;

src/libstd/collections/hash/set.rs

@@ -1067,8 +1067,6 @@ fn assert_covariance() {
 
 #[cfg(test)]
 mod test_set {
-    use prelude::v1::*;
-
     use super::HashSet;
 
     #[test]

src/libstd/env.rs

@@ -16,8 +16,6 @@
 
 #![stable(feature = "env", since = "1.0.0")]
 
-use prelude::v1::*;
-
 use error::Error;
 use ffi::{OsStr, OsString};
 use fmt;
@@ -950,7 +948,6 @@ mod arch {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use super::*;
 
     use iter::repeat;

src/libstd/error.rs

@@ -48,16 +48,15 @@
 // reconsider what crate these items belong in.
 
 use any::TypeId;
-use boxed::Box;
 use cell;
 use char;
 use fmt::{self, Debug, Display};
-use marker::{Send, Sync, Reflect};
+use marker::Reflect;
 use mem::transmute;
 use num;
 use raw::TraitObject;
 use str;
-use string::{self, String};
+use string;
 
 /// Base functionality for all errors in Rust.
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -454,7 +453,6 @@ impl Error + Send + Sync {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use super::Error;
     use fmt;
 

src/libstd/ffi/c_str.rs

@@ -9,25 +9,18 @@
 // except according to those terms.
 
 use ascii;
-use borrow::{Cow, ToOwned, Borrow};
-use boxed::Box;
-use convert::{Into, From};
-use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
+use borrow::{Cow, Borrow};
+use cmp::Ordering;
 use error::Error;
 use fmt::{self, Write};
 use io;
-use iter::Iterator;
 use libc;
 use mem;
 use memchr;
 use ops;
-use option::Option::{self, Some, None};
 use os::raw::c_char;
-use result::Result::{self, Ok, Err};
 use slice;
 use str::{self, Utf8Error};
-use string::String;
-use vec::Vec;
 
 /// A type representing an owned C-compatible string
 ///
@@ -700,7 +693,6 @@ impl AsRef<CStr> for CString {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use super::*;
     use os::raw::c_char;
     use borrow::Cow::{Borrowed, Owned};

src/libstd/ffi/os_str.rs

@@ -8,14 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use borrow::{Borrow, Cow, ToOwned};
+use borrow::{Borrow, Cow};
 use fmt::{self, Debug};
 use mem;
-use string::String;
 use ops;
 use cmp;
 use hash::{Hash, Hasher};
-use vec::Vec;
 
 use sys::os_str::{Buf, Slice};
 use sys_common::{AsInner, IntoInner, FromInner};

src/libstd/fs.rs

@@ -23,7 +23,6 @@ use io::{self, SeekFrom, Seek, Read, Write};
 use path::{Path, PathBuf};
 use sys::fs as fs_imp;
 use sys_common::{AsInnerMut, FromInner, AsInner, IntoInner};
-use vec::Vec;
 use time::SystemTime;
 
 /// A reference to an open file on the filesystem.
@@ -1677,7 +1676,6 @@ impl AsInnerMut<fs_imp::DirBuilder> for DirBuilder {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use io::prelude::*;
 
     use fs::{self, File, OpenOptions};

src/libstd/io/buffered.rs

@@ -10,7 +10,6 @@
 
 //! Buffering wrappers for I/O traits
 
-use prelude::v1::*;
 use io::prelude::*;
 
 use marker::Reflect;
@@ -788,7 +787,6 @@ impl<W: Write> fmt::Debug for LineWriter<W> where W: fmt::Debug {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use io::prelude::*;
     use io::{self, BufReader, BufWriter, LineWriter, SeekFrom};
     use sync::atomic::{AtomicUsize, Ordering};

src/libstd/io/cursor.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
 use io::prelude::*;
 
 use cmp;
@@ -284,7 +283,6 @@ impl Write for Cursor<Box<[u8]>> {
 mod tests {
     use io::prelude::*;
     use io::{Cursor, SeekFrom};
-    use vec::Vec;
 
     #[test]
     fn test_vec_writer() {

src/libstd/io/error.rs

@@ -8,12 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use boxed::Box;
-use convert::Into;
 use error;
 use fmt;
-use marker::{Send, Sync};
-use option::Option::{self, Some, None};
 use result;
 use sys;
 
@@ -522,7 +518,6 @@ fn _assert_error_is_sync_send() {
 
 #[cfg(test)]
 mod test {
-    use prelude::v1::*;
     use super::{Error, ErrorKind};
     use error;
     use fmt;

src/libstd/io/impls.rs

@@ -8,13 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use boxed::Box;
 use cmp;
 use io::{self, SeekFrom, Read, Write, Seek, BufRead, Error, ErrorKind};
 use fmt;
 use mem;
-use string::String;
-use vec::Vec;
 
 // =============================================================================
 // Forwarding implementations
@@ -228,7 +225,6 @@ impl Write for Vec<u8> {
 #[cfg(test)]
 mod tests {
     use io::prelude::*;
-    use vec::Vec;
     use test;
 
     #[bench]

src/libstd/io/lazy.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use cell::Cell;
 use ptr;
 use sync::Arc;

src/libstd/io/mod.rs

@@ -253,15 +253,8 @@ use cmp;
 use rustc_unicode::str as core_str;
 use error as std_error;
 use fmt;
-use iter::{Iterator};
-use marker::Sized;
-use ops::{Drop, FnOnce};
-use option::Option::{self, Some, None};
-use result::Result::{Ok, Err};
 use result;
-use string::String;
 use str;
-use vec::Vec;
 use memchr;
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1734,7 +1727,6 @@ impl<B: BufRead> Iterator for Lines<B> {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use io::prelude::*;
     use io;
     use super::Cursor;

src/libstd/io/stdio.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
 use io::prelude::*;
 
 use cell::{RefCell, BorrowState};

src/libstd/io/util.rs

@@ -167,8 +167,6 @@ impl Write for Sink {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use io::prelude::*;
     use io::{copy, sink, empty, repeat};
 

src/libstd/lib.rs

@@ -252,6 +252,7 @@
 #![feature(optin_builtin_traits)]
 #![feature(panic_unwind)]
 #![feature(placement_in_syntax)]
+#![feature(prelude_import)]
 #![feature(question_mark)]
 #![feature(rand)]
 #![feature(raw)]
@@ -292,6 +293,10 @@
 #![allow(unused_features)] // std may use features in a platform-specific way
 #![cfg_attr(not(stage0), deny(warnings))]
 
+#[prelude_import]
+#[allow(unused)]
+use prelude::v1::*;
+
 #[cfg(test)] extern crate test;
 
 // We want to reexport a few macros from core but libcore has already been

src/libstd/net/addr.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use fmt;
 use hash;
 use io;
@@ -523,7 +521,6 @@ impl<'a, T: ToSocketAddrs + ?Sized> ToSocketAddrs for &'a T {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use net::*;
     use net::test::{tsa, sa6, sa4};
 

src/libstd/net/ip.rs

@@ -653,7 +653,6 @@ impl From<[u8; 16]> for Ipv6Addr {
 // Tests for this module
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use net::*;
     use net::Ipv6MulticastScope::*;
     use net::test::{tsa, sa6, sa4};

src/libstd/net/mod.rs

@@ -12,8 +12,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::v1::*;
-
 use io::{self, Error, ErrorKind};
 use sys_common::net as net_imp;
 

src/libstd/net/parser.rs

@@ -13,8 +13,6 @@
 //! This module is "publicly exported" through the `FromStr` implementations
 //! below.
 
-use prelude::v1::*;
-
 use error::Error;
 use fmt;
 use net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};

src/libstd/net/tcp.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
 use io::prelude::*;
 
 use fmt;
@@ -438,8 +437,6 @@ impl fmt::Debug for TcpListener {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use io::ErrorKind;
     use io::prelude::*;
     use net::*;

src/libstd/net/test.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use env;
 use net::{SocketAddr, SocketAddrV4, SocketAddrV6, Ipv4Addr, Ipv6Addr, ToSocketAddrs};
 use sync::atomic::{AtomicUsize, Ordering};

src/libstd/net/udp.rs

@@ -355,8 +355,6 @@ impl fmt::Debug for UdpSocket {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use io::ErrorKind;
     use net::*;
     use net::test::{next_test_ip4, next_test_ip6};

src/libstd/num/mod.rs

@@ -24,9 +24,7 @@ pub use core::num::{FpCategory, ParseIntError, ParseFloatError, TryFromIntError}
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::num::Wrapping;
 
-#[cfg(test)] use cmp::PartialEq;
 #[cfg(test)] use fmt;
-#[cfg(test)] use marker::Copy;
 #[cfg(test)] use ops::{Add, Sub, Mul, Div, Rem};
 
 /// Helper function for testing numeric operations
@@ -52,7 +50,6 @@ mod tests {
     use u32;
     use u64;
     use usize;
-    use string::ToString;
     use ops::Mul;
 
     #[test]
@@ -287,7 +284,6 @@ mod tests {
 mod bench {
     extern crate test;
     use self::test::Bencher;
-    use prelude::v1::*;
 
     #[bench]
     fn bench_pow_function(b: &mut Bencher) {

src/libstd/panic.rs

@@ -13,7 +13,6 @@
 #![stable(feature = "std_panic", since = "1.9.0")]
 
 use any::Any;
-use boxed::Box;
 use cell::UnsafeCell;
 use ops::{Deref, DerefMut};
 use panicking;

src/libstd/panicking.rs

@@ -17,7 +17,6 @@
 //! * Executing a panic up to doing the actual implementation
 //! * Shims around "try"
 
-use prelude::v1::*;
 use io::prelude::*;
 
 use any::Any;

src/libstd/path.rs

@@ -100,7 +100,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use ascii::*;
-use borrow::{Borrow, ToOwned, Cow};
+use borrow::{Borrow, Cow};
 use cmp;
 use error::Error;
 use fmt;
@@ -110,8 +110,6 @@ use io;
 use iter::{self, FusedIterator};
 use mem;
 use ops::{self, Deref};
-use string::String;
-use vec::Vec;
 
 use ffi::{OsStr, OsString};
 
@@ -2152,8 +2150,6 @@ impl Error for StripPrefixError {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use string::{ToString, String};
-    use vec::Vec;
 
     macro_rules! t(
         ($path:expr, iter: $iter:expr) => (

src/libstd/process.rs

@@ -12,7 +12,6 @@
 
 #![stable(feature = "process", since = "1.0.0")]
 
-use prelude::v1::*;
 use io::prelude::*;
 
 use ffi::OsStr;
@@ -810,7 +809,6 @@ pub fn exit(code: i32) -> ! {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use io::prelude::*;
 
     use io::ErrorKind;

src/libstd/rt.rs

@@ -30,7 +30,6 @@ pub use panicking::{begin_panic, begin_panic_fmt, update_panic_count};
 #[cfg(not(test))]
 #[lang = "start"]
 fn lang_start(main: *const u8, argc: isize, argv: *const *const u8) -> isize {
-    use borrow::ToOwned;
     use mem;
     use panic;
     use sys;

src/libstd/sync/barrier.rs

@@ -113,8 +113,6 @@ impl BarrierWaitResult {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use sync::{Arc, Barrier};
     use sync::mpsc::{channel, TryRecvError};
     use thread;

src/libstd/sync/condvar.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use sync::atomic::{AtomicUsize, Ordering};
 use sync::{mutex, MutexGuard, PoisonError};
 use sys_common::condvar as sys;
@@ -245,8 +243,6 @@ impl Drop for Condvar {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use sync::mpsc::channel;
     use sync::{Condvar, Mutex, Arc};
     use thread;

src/libstd/sync/mpsc/blocking.rs

@@ -13,9 +13,7 @@
 use thread::{self, Thread};
 use sync::atomic::{AtomicBool, Ordering};
 use sync::Arc;
-use marker::{Sync, Send};
 use mem;
-use clone::Clone;
 use time::Instant;
 
 struct Inner {

src/libstd/sync/mpsc/mod.rs

@@ -1270,8 +1270,6 @@ impl error::Error for TryRecvError {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use env;
     use super::*;
     use thread;
@@ -1946,8 +1944,6 @@ mod tests {
 
 #[cfg(test)]
 mod sync_tests {
-    use prelude::v1::*;
-
     use env;
     use thread;
     use super::*;

src/libstd/sync/mpsc/mpsc_queue.rs

@@ -148,8 +148,6 @@ impl<T> Drop for Queue<T> {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use sync::mpsc::channel;
     use super::{Queue, Data, Empty, Inconsistent};
     use sync::Arc;

src/libstd/sync/mpsc/select.rs

@@ -369,8 +369,6 @@ impl<'rx, T:Send+'rx> fmt::Debug for Handle<'rx, T> {
 #[cfg(test)]
 #[allow(unused_imports)]
 mod tests {
-    use prelude::v1::*;
-
     use thread;
     use sync::mpsc::*;
 

src/libstd/sync/mpsc/spsc_queue.rs

@@ -233,8 +233,6 @@ impl<T> Drop for Queue<T> {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use sync::Arc;
     use super::Queue;
     use thread;

src/libstd/sync/mpsc/sync.rs

@@ -36,7 +36,6 @@
 pub use self::Failure::*;
 use self::Blocker::*;
 
-use vec::Vec;
 use core::mem;
 use core::ptr;
 

src/libstd/sync/mutex.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use cell::UnsafeCell;
 use fmt;
 use marker;
@@ -355,8 +353,6 @@ pub fn guard_poison<'a, T: ?Sized>(guard: &MutexGuard<'a, T>) -> &'a poison::Fla
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use sync::mpsc::channel;
     use sync::{Arc, Mutex, Condvar};
     use sync::atomic::{AtomicUsize, Ordering};

src/libstd/sync/once.rs

@@ -369,8 +369,6 @@ impl OnceState {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use panic;
     use sync::mpsc::channel;
     use thread;

src/libstd/sync/rwlock.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use cell::UnsafeCell;
 use fmt;
 use marker;
@@ -385,8 +383,6 @@ impl<'a, T: ?Sized> Drop for RwLockWriteGuard<'a, T> {
 mod tests {
     #![allow(deprecated)] // rand
 
-    use prelude::v1::*;
-
     use rand::{self, Rng};
     use sync::mpsc::channel;
     use thread;
@@ -552,8 +548,6 @@ mod tests {
 
     #[test]
     fn test_rwlock_try_write() {
-        use mem::drop;
-
         let lock = RwLock::new(0isize);
         let read_guard = lock.read().unwrap();
 

src/libstd/sys/common/args.rs

@@ -21,8 +21,6 @@
 
 #![allow(dead_code)] // different code on OSX/linux/etc
 
-use vec::Vec;
-
 /// One-time global initialization.
 pub unsafe fn init(argc: isize, argv: *const *const u8) { imp::init(argc, argv) }
 
@@ -42,8 +40,6 @@ pub fn clone() -> Option<Vec<Vec<u8>>> { imp::clone() }
           target_os = "solaris",
           target_os = "emscripten"))]
 mod imp {
-    use prelude::v1::*;
-
     use libc::c_char;
     use mem;
     use ffi::CStr;
@@ -91,8 +87,6 @@ mod imp {
           target_os = "ios",
           target_os = "windows"))]
 mod imp {
-    use vec::Vec;
-
     pub unsafe fn init(_argc: isize, _argv: *const *const u8) {
     }
 

src/libstd/sys/common/at_exit_imp.rs

@@ -13,10 +13,8 @@
 //! Documentation can be found on the `rt::at_exit` function.
 
 use alloc::boxed::FnBox;
-use boxed::Box;
 use ptr;
 use sys_common::mutex::Mutex;
-use vec::Vec;
 
 type Queue = Vec<Box<FnBox()>>;
 

src/libstd/sys/common/backtrace.rs

@@ -191,7 +191,6 @@ pub fn demangle(writer: &mut Write, s: &str) -> io::Result<()> {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use sys_common;
     macro_rules! t { ($a:expr, $b:expr) => ({
         let mut m = Vec::new();

src/libstd/sys/common/io.rs

@@ -7,7 +7,6 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-use prelude::v1::*;
 use io;
 use io::ErrorKind;
 use io::Read;
@@ -53,7 +52,6 @@ pub unsafe fn read_to_end_uninitialized(r: &mut Read, buf: &mut Vec<u8>) -> io::
 
 #[cfg(test)]
 pub mod test {
-    use prelude::v1::*;
     use path::{Path, PathBuf};
     use env;
     use rand::{self, Rng};
@@ -93,7 +91,6 @@ pub mod test {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use io::prelude::*;
     use super::*;
     use io;

src/libstd/sys/common/mod.rs

@@ -10,7 +10,6 @@
 
 #![allow(missing_docs)]
 
-use boxed::Box;
 use sync::Once;
 use sys;
 

src/libstd/sys/common/mutex.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use marker::Sync;
 use sys::mutex as imp;
 
 /// An OS-based mutual exclusion lock.

src/libstd/sys/common/net.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use cmp;
 use ffi::CString;
 use fmt;
@@ -608,8 +606,6 @@ impl fmt::Debug for UdpSocket {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
-
     use super::*;
     use collections::HashMap;
 

src/libstd/sys/common/remutex.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::v1::*;
-
 use fmt;
 use marker;
 use ops::Deref;
@@ -160,7 +158,6 @@ impl<'a, T> Drop for ReentrantMutexGuard<'a, T> {
 
 #[cfg(test)]
 mod tests {
-    use prelude::v1::*;
     use sys_common::remutex::{ReentrantMutex, ReentrantMutexGuard};
     use cell::RefCell;
     use sync::Arc;