Use Rust 2021 prelude in std itself.

39 files changed, 7 insertions, 43 deletions

diff --git a/library/std/src/collections/hash/map.rs b/library/std/src/collections/hash/map.rs
index e38368790e6..977714281fb 100644
--- a/library/std/src/collections/hash/map.rs
+++ b/library/std/src/collections/hash/map.rs
@@ -12,7 +12,7 @@ use crate::collections::TryReserveErrorKind;
 use crate::fmt::{self, Debug};
 #[allow(deprecated)]
 use crate::hash::{BuildHasher, Hash, Hasher, SipHasher13};
-use crate::iter::{FromIterator, FusedIterator};
+use crate::iter::FusedIterator;
 use crate::ops::Index;
 use crate::sys;
 
diff --git a/library/std/src/collections/hash/set.rs b/library/std/src/collections/hash/set.rs
index fa471a3c3f3..13bba0a6fd8 100644
--- a/library/std/src/collections/hash/set.rs
+++ b/library/std/src/collections/hash/set.rs
@@ -7,7 +7,7 @@ use crate::borrow::Borrow;
 use crate::collections::TryReserveError;
 use crate::fmt;
 use crate::hash::{BuildHasher, Hash};
-use crate::iter::{Chain, FromIterator, FusedIterator};
+use crate::iter::{Chain, FusedIterator};
 use crate::ops::{BitAnd, BitOr, BitXor, Sub};
 
 use super::map::{map_try_reserve_error, RandomState};
diff --git a/library/std/src/ffi/os_str.rs b/library/std/src/ffi/os_str.rs
index dd316bdb2c6..810d85554aa 100644
--- a/library/std/src/ffi/os_str.rs
+++ b/library/std/src/ffi/os_str.rs
@@ -6,7 +6,7 @@ use crate::cmp;
 use crate::collections::TryReserveError;
 use crate::fmt;
 use crate::hash::{Hash, Hasher};
-use crate::iter::{Extend, FromIterator};
+use crate::iter::Extend;
 use crate::ops;
 use crate::rc::Rc;
 use crate::str::FromStr;
diff --git a/library/std/src/io/cursor.rs b/library/std/src/io/cursor.rs
index 57f1d628f6a..0ce6ae00ee2 100644
--- a/library/std/src/io/cursor.rs
+++ b/library/std/src/io/cursor.rs
@@ -7,8 +7,6 @@ use crate::alloc::Allocator;
 use crate::cmp;
 use crate::io::{self, ErrorKind, IoSlice, IoSliceMut, ReadBuf, SeekFrom};
 
-use core::convert::TryInto;
-
 /// A `Cursor` wraps an in-memory buffer and provides it with a
 /// [`Seek`] implementation.
 ///
diff --git a/library/std/src/io/mod.rs b/library/std/src/io/mod.rs
index cd2197fca35..94812e3fe3b 100644
--- a/library/std/src/io/mod.rs
+++ b/library/std/src/io/mod.rs
@@ -252,7 +252,6 @@
 mod tests;
 
 use crate::cmp;
-use crate::convert::TryInto;
 use crate::fmt;
 use crate::mem::replace;
 use crate::ops::{Deref, DerefMut};
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index c394865d886..519f050d2fc 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -345,7 +345,7 @@
 // to import the prelude implicitly when building crates that depend on std.
 #[prelude_import]
 #[allow(unused)]
-use prelude::v1::*;
+use prelude::rust_2021::*;
 
 // Access to Bencher, etc.
 #[cfg(test)]
diff --git a/library/std/src/net/addr.rs b/library/std/src/net/addr.rs
index 201cbf3f08d..81dd042425c 100644
--- a/library/std/src/net/addr.rs
+++ b/library/std/src/net/addr.rs
@@ -2,7 +2,6 @@
 mod tests;
 
 use crate::cmp::Ordering;
-use crate::convert::TryInto;
 use crate::fmt;
 use crate::hash;
 use crate::io::{self, Write};
diff --git a/library/std/src/net/parser.rs b/library/std/src/net/parser.rs
index fb292ed29a1..069b6609985 100644
--- a/library/std/src/net/parser.rs
+++ b/library/std/src/net/parser.rs
@@ -6,7 +6,6 @@
 #[cfg(test)]
 mod tests;
 
-use crate::convert::TryInto as _;
 use crate::error::Error;
 use crate::fmt;
 use crate::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
diff --git a/library/std/src/os/unix/net/ancillary.rs b/library/std/src/os/unix/net/ancillary.rs
index 658c79896eb..9e31b8b32a1 100644
--- a/library/std/src/os/unix/net/ancillary.rs
+++ b/library/std/src/os/unix/net/ancillary.rs
@@ -1,5 +1,4 @@
 use super::{sockaddr_un, SocketAddr};
-use crate::convert::TryFrom;
 use crate::io::{self, IoSlice, IoSliceMut};
 use crate::marker::PhantomData;
 use crate::mem::{size_of, zeroed};
diff --git a/library/std/src/os/unix/net/tests.rs b/library/std/src/os/unix/net/tests.rs
index aa0df61c192..c1f11c56b8f 100644
--- a/library/std/src/os/unix/net/tests.rs
+++ b/library/std/src/os/unix/net/tests.rs
@@ -10,7 +10,6 @@ use crate::io::{self, ErrorKind, IoSlice, IoSliceMut};
     target_os = "netbsd",
     target_os = "openbsd",
 ))]
-use crate::iter::FromIterator;
 #[cfg(any(
     target_os = "android",
     target_os = "dragonfly",
diff --git a/library/std/src/os/windows/io/handle.rs b/library/std/src/os/windows/io/handle.rs
index f3d7be3f95c..41758f2ced1 100644
--- a/library/std/src/os/windows/io/handle.rs
+++ b/library/std/src/os/windows/io/handle.rs
@@ -3,7 +3,6 @@
 #![unstable(feature = "io_safety", issue = "87074")]
 
 use super::raw::{AsRawHandle, FromRawHandle, IntoRawHandle, RawHandle};
-use crate::convert::TryFrom;
 use crate::fmt;
 use crate::fs;
 use crate::io;
diff --git a/library/std/src/sys/hermit/net.rs b/library/std/src/sys/hermit/net.rs
index f65fd8e53bd..74547617150 100644
--- a/library/std/src/sys/hermit/net.rs
+++ b/library/std/src/sys/hermit/net.rs
@@ -1,4 +1,3 @@
-use crate::convert::TryFrom;
 use crate::fmt;
 use crate::io::{self, ErrorKind, IoSlice, IoSliceMut};
 use crate::net::{IpAddr, Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr};
diff --git a/library/std/src/sys/hermit/time.rs b/library/std/src/sys/hermit/time.rs
index 27173de6307..c17e6c8af62 100644
--- a/library/std/src/sys/hermit/time.rs
+++ b/library/std/src/sys/hermit/time.rs
@@ -1,7 +1,6 @@
 #![allow(dead_code)]
 
 use crate::cmp::Ordering;
-use crate::convert::TryInto;
 use crate::sys::hermit::abi;
 use crate::sys::hermit::abi::timespec;
 use crate::sys::hermit::abi::{CLOCK_MONOTONIC, CLOCK_REALTIME, NSEC_PER_SEC};
diff --git a/library/std/src/sys/itron/spin.rs b/library/std/src/sys/itron/spin.rs
index d0149d1f037..44d409444bc 100644
--- a/library/std/src/sys/itron/spin.rs
+++ b/library/std/src/sys/itron/spin.rs
@@ -1,7 +1,6 @@
 use super::abi;
 use crate::{
     cell::UnsafeCell,
-    convert::TryFrom,
     mem::MaybeUninit,
     sync::atomic::{AtomicBool, AtomicUsize, Ordering},
 };
diff --git a/library/std/src/sys/itron/thread.rs b/library/std/src/sys/itron/thread.rs
index 5b718a460df..d28f57f33be 100644
--- a/library/std/src/sys/itron/thread.rs
+++ b/library/std/src/sys/itron/thread.rs
@@ -8,7 +8,6 @@ use super::{
 };
 use crate::{
     cell::UnsafeCell,
-    convert::TryFrom,
     ffi::CStr,
     hint, io,
     mem::ManuallyDrop,
diff --git a/library/std/src/sys/itron/time.rs b/library/std/src/sys/itron/time.rs
index 25f13ee441a..427ea0d80e1 100644
--- a/library/std/src/sys/itron/time.rs
+++ b/library/std/src/sys/itron/time.rs
@@ -1,5 +1,5 @@
 use super::{abi, error::expect_success};
-use crate::{convert::TryInto, mem::MaybeUninit, time::Duration};
+use crate::{mem::MaybeUninit, time::Duration};
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct Instant(abi::SYSTIM);
diff --git a/library/std/src/sys/sgx/abi/usercalls/mod.rs b/library/std/src/sys/sgx/abi/usercalls/mod.rs
index 4030355f135..2f99abba776 100644
--- a/library/std/src/sys/sgx/abi/usercalls/mod.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/mod.rs
@@ -1,5 +1,4 @@
 use crate::cmp;
-use crate::convert::TryFrom;
 use crate::io::{Error as IoError, ErrorKind, IoSlice, IoSliceMut, Result as IoResult};
 use crate::sys::rand::rdrand64;
 use crate::time::{Duration, Instant};
diff --git a/library/std/src/sys/sgx/net.rs b/library/std/src/sys/sgx/net.rs
index feb0b62dcd1..1d899525081 100644
--- a/library/std/src/sys/sgx/net.rs
+++ b/library/std/src/sys/sgx/net.rs
@@ -1,4 +1,3 @@
-use crate::convert::TryFrom;
 use crate::error;
 use crate::fmt;
 use crate::io::{self, IoSlice, IoSliceMut};
diff --git a/library/std/src/sys/solid/time.rs b/library/std/src/sys/solid/time.rs
index ab988be2444..ce31cb45a69 100644
--- a/library/std/src/sys/solid/time.rs
+++ b/library/std/src/sys/solid/time.rs
@@ -1,5 +1,5 @@
 use super::{abi, error::expect_success};
-use crate::{convert::TryInto, mem::MaybeUninit, time::Duration};
+use crate::{mem::MaybeUninit, time::Duration};
 
 pub use super::itron::time::Instant;
 
diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs
index 61fb2814018..5d0fb079003 100644
--- a/library/std/src/sys/unix/fs.rs
+++ b/library/std/src/sys/unix/fs.rs
@@ -943,7 +943,6 @@ impl File {
     }
 
     pub fn truncate(&self, size: u64) -> io::Result<()> {
-        use crate::convert::TryInto;
         let size: off64_t =
             size.try_into().map_err(|e| io::Error::new(io::ErrorKind::InvalidInput, e))?;
         cvt_r(|| unsafe { ftruncate64(self.as_raw_fd(), size) }).map(drop)
diff --git a/library/std/src/sys/unix/futex.rs b/library/std/src/sys/unix/futex.rs
index c1966d67078..8d5ad18997d 100644
--- a/library/std/src/sys/unix/futex.rs
+++ b/library/std/src/sys/unix/futex.rs
@@ -136,7 +136,6 @@ pub fn futex_wake_all(futex: &AtomicU32) {
 
 #[cfg(target_os = "openbsd")]
 pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) -> bool {
-    use crate::convert::TryInto;
     use crate::ptr::{null, null_mut};
     let timespec = timeout.and_then(|d| {
         Some(libc::timespec {
@@ -185,8 +184,6 @@ pub fn futex_wake_all(futex: &AtomicU32) {
 
 #[cfg(target_os = "dragonfly")]
 pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) -> bool {
-    use crate::convert::TryFrom;
-
     // A timeout of 0 means infinite.
     // We round smaller timeouts up to 1 millisecond.
     // Overflows are rounded up to an infinite timeout.
diff --git a/library/std/src/sys/unix/kernel_copy.rs b/library/std/src/sys/unix/kernel_copy.rs
index e85e4c5d618..8f7abb55e23 100644
--- a/library/std/src/sys/unix/kernel_copy.rs
+++ b/library/std/src/sys/unix/kernel_copy.rs
@@ -45,7 +45,6 @@
 //! * complexity
 
 use crate::cmp::min;
-use crate::convert::TryInto;
 use crate::fs::{File, Metadata};
 use crate::io::copy::generic_copy;
 use crate::io::{
diff --git a/library/std/src/sys/unix/l4re.rs b/library/std/src/sys/unix/l4re.rs
index f052d8f7f05..9967588939a 100644
--- a/library/std/src/sys/unix/l4re.rs
+++ b/library/std/src/sys/unix/l4re.rs
@@ -9,7 +9,6 @@ macro_rules! unimpl {
 
 pub mod net {
     #![allow(warnings)]
-    use crate::convert::TryFrom;
     use crate::fmt;
     use crate::io::{self, IoSlice, IoSliceMut};
     use crate::net::{Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr};
diff --git a/library/std/src/sys/unix/process/process_fuchsia.rs b/library/std/src/sys/unix/process/process_fuchsia.rs
index e3347ab12a7..73f5d3a618b 100644
--- a/library/std/src/sys/unix/process/process_fuchsia.rs
+++ b/library/std/src/sys/unix/process/process_fuchsia.rs
@@ -1,4 +1,3 @@
-use crate::convert::{TryFrom, TryInto};
 use crate::fmt;
 use crate::io;
 use crate::mem;
diff --git a/library/std/src/sys/unix/process/process_unix.rs b/library/std/src/sys/unix/process/process_unix.rs
index d48faaa88fb..23bb6d6c15f 100644
--- a/library/std/src/sys/unix/process/process_unix.rs
+++ b/library/std/src/sys/unix/process/process_unix.rs
@@ -1,4 +1,3 @@
-use crate::convert::{TryFrom, TryInto};
 use crate::fmt;
 use crate::io::{self, Error, ErrorKind};
 use crate::mem;
diff --git a/library/std/src/sys/unix/process/process_unsupported.rs b/library/std/src/sys/unix/process/process_unsupported.rs
index bbabdf787d9..5db57ee9e9e 100644
--- a/library/std/src/sys/unix/process/process_unsupported.rs
+++ b/library/std/src/sys/unix/process/process_unsupported.rs
@@ -1,4 +1,3 @@
-use crate::convert::{TryFrom, TryInto};
 use crate::fmt;
 use crate::io;
 use crate::io::ErrorKind;
diff --git a/library/std/src/sys/unix/process/process_vxworks.rs b/library/std/src/sys/unix/process/process_vxworks.rs
index 016bc20ec0a..200ef671967 100644
--- a/library/std/src/sys/unix/process/process_vxworks.rs
+++ b/library/std/src/sys/unix/process/process_vxworks.rs
@@ -1,4 +1,3 @@
-use crate::convert::{TryFrom, TryInto};
 use crate::fmt;
 use crate::io::{self, Error, ErrorKind};
 use crate::num::NonZeroI32;
diff --git a/library/std/src/sys/unix/process/zircon.rs b/library/std/src/sys/unix/process/zircon.rs
index 4dfa2b4ff1e..2e596486f9c 100644
--- a/library/std/src/sys/unix/process/zircon.rs
+++ b/library/std/src/sys/unix/process/zircon.rs
@@ -1,6 +1,5 @@
 #![allow(non_camel_case_types, unused)]
 
-use crate::convert::TryInto;
 use crate::io;
 use crate::mem::MaybeUninit;
 use crate::os::raw::c_char;
diff --git a/library/std/src/sys/unix/time.rs b/library/std/src/sys/unix/time.rs
index ac8355188bb..333182bdad4 100644
--- a/library/std/src/sys/unix/time.rs
+++ b/library/std/src/sys/unix/time.rs
@@ -2,7 +2,6 @@ use crate::fmt;
 use crate::time::Duration;
 
 pub use self::inner::Instant;
-use crate::convert::TryInto;
 
 const NSEC_PER_SEC: u64 = 1_000_000_000;
 pub const UNIX_EPOCH: SystemTime = SystemTime { t: Timespec::zero() };
@@ -127,7 +126,6 @@ impl Timespec {
     }
 
     pub fn to_timespec(&self) -> Option<libc::timespec> {
-        use crate::convert::TryInto;
         Some(libc::timespec {
             tv_sec: self.tv_sec.try_into().ok()?,
             tv_nsec: self.tv_nsec.try_into().ok()?,
diff --git a/library/std/src/sys/unsupported/net.rs b/library/std/src/sys/unsupported/net.rs
index dbb6ce22c22..360115d5033 100644
--- a/library/std/src/sys/unsupported/net.rs
+++ b/library/std/src/sys/unsupported/net.rs
@@ -1,4 +1,3 @@
-use crate::convert::TryFrom;
 use crate::fmt;
 use crate::io::{self, IoSlice, IoSliceMut};
 use crate::net::{Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr};
diff --git a/library/std/src/sys/wasi/net.rs b/library/std/src/sys/wasi/net.rs
index c66e0e4d328..937b1b850e7 100644
--- a/library/std/src/sys/wasi/net.rs
+++ b/library/std/src/sys/wasi/net.rs
@@ -2,7 +2,6 @@
 
 use super::err2io;
 use super::fd::WasiFd;
-use crate::convert::TryFrom;
 use crate::fmt;
 use crate::io::{self, IoSlice, IoSliceMut};
 use crate::net::{Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr};
diff --git a/library/std/src/sys/wasm/atomics/futex.rs b/library/std/src/sys/wasm/atomics/futex.rs
index 11413ba3bf5..f4fbe9f4855 100644
--- a/library/std/src/sys/wasm/atomics/futex.rs
+++ b/library/std/src/sys/wasm/atomics/futex.rs
@@ -1,5 +1,4 @@
 use crate::arch::wasm32;
-use crate::convert::TryInto;
 use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
diff --git a/library/std/src/sys/windows/fs.rs b/library/std/src/sys/windows/fs.rs
index 95903899297..157d8a044d3 100644
--- a/library/std/src/sys/windows/fs.rs
+++ b/library/std/src/sys/windows/fs.rs
@@ -1,6 +1,5 @@
 use crate::os::windows::prelude::*;
 
-use crate::convert::TryInto;
 use crate::ffi::OsString;
 use crate::fmt;
 use crate::io::{self, Error, IoSlice, IoSliceMut, ReadBuf, SeekFrom};
diff --git a/library/std/src/sys/windows/process.rs b/library/std/src/sys/windows/process.rs
index cc29d1a72fb..224063cad36 100644
--- a/library/std/src/sys/windows/process.rs
+++ b/library/std/src/sys/windows/process.rs
@@ -5,7 +5,6 @@ mod tests;
 
 use crate::cmp;
 use crate::collections::BTreeMap;
-use crate::convert::{TryFrom, TryInto};
 use crate::env;
 use crate::env::consts::{EXE_EXTENSION, EXE_SUFFIX};
 use crate::ffi::{OsStr, OsString};
diff --git a/library/std/src/sys/windows/thread.rs b/library/std/src/sys/windows/thread.rs
index 2f469513eb4..c5c9e97e646 100644
--- a/library/std/src/sys/windows/thread.rs
+++ b/library/std/src/sys/windows/thread.rs
@@ -1,4 +1,3 @@
-use crate::convert::TryInto;
 use crate::ffi::CStr;
 use crate::io;
 use crate::num::NonZeroUsize;
diff --git a/library/std/src/sys/windows/thread_parker.rs b/library/std/src/sys/windows/thread_parker.rs
index 51448344475..d876e0f6f3c 100644
--- a/library/std/src/sys/windows/thread_parker.rs
+++ b/library/std/src/sys/windows/thread_parker.rs
@@ -57,7 +57,6 @@
 // [3]: https://docs.microsoft.com/en-us/archive/msdn-magazine/2012/november/windows-with-c-the-evolution-of-synchronization-in-windows-and-c
 // [4]: Windows Internals, Part 1, ISBN 9780735671300
 
-use crate::convert::TryFrom;
 use crate::pin::Pin;
 use crate::ptr;
 use crate::sync::atomic::{
diff --git a/library/std/src/sys/windows/time.rs b/library/std/src/sys/windows/time.rs
index a04908b541c..8f46781c753 100644
--- a/library/std/src/sys/windows/time.rs
+++ b/library/std/src/sys/windows/time.rs
@@ -1,5 +1,4 @@
 use crate::cmp::Ordering;
-use crate::convert::TryInto;
 use crate::fmt;
 use crate::mem;
 use crate::sys::c;
diff --git a/library/std/src/sys_common/net.rs b/library/std/src/sys_common/net.rs
index 3b7cdd55a08..05425f4a362 100644
--- a/library/std/src/sys_common/net.rs
+++ b/library/std/src/sys_common/net.rs
@@ -2,7 +2,6 @@
 mod tests;
 
 use crate::cmp;
-use crate::convert::{TryFrom, TryInto};
 use crate::ffi::CString;
 use crate::fmt;
 use crate::io::{self, ErrorKind, IoSlice, IoSliceMut};
diff --git a/library/std/src/sys_common/wtf8.rs b/library/std/src/sys_common/wtf8.rs
index 7d66973bed6..57fa4989358 100644
--- a/library/std/src/sys_common/wtf8.rs
+++ b/library/std/src/sys_common/wtf8.rs
@@ -25,7 +25,7 @@ use crate::char;
 use crate::collections::TryReserveError;
 use crate::fmt;
 use crate::hash::{Hash, Hasher};
-use crate::iter::{FromIterator, FusedIterator};
+use crate::iter::FusedIterator;
 use crate::mem;
 use crate::ops;
 use crate::rc::Rc;