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

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

r? @eddyb

Author: bors

Diff for: 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;

Diff for: 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;
 

Diff for: 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.

Diff for: 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

Diff for: 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;

Diff for: 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

Diff for: 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
 ///

Diff for: 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

Diff for: 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.
 ///

Diff for: 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;

Diff for: 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 {

Diff for: 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

Diff for: 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)*) => ($(

Diff for: 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

Diff for: 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

Diff for: 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> {

Diff for: 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

Diff for: 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};

Diff for: 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::*;

Diff for: src/libcore/hash/sip.rs

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

Diff for: 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

Diff for: 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=()>) {}
 

Diff for: 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")]

Diff for: 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.
 ///

Diff for: 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.
 ///

Diff for: 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

Diff for: 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

Diff for: 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;

Diff for: 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")]