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

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

r? @eddyb

Author: bors

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;