Rollup of 7 pull requests

src/liballoc/boxed.rs

@@ -865,6 +865,25 @@ impl From<Box<str>> for Box<[u8]> {
     }
 }
 
+#[stable(feature = "box_from_array", since = "1.45.0")]
+impl<T, const N: usize> From<[T; N]> for Box<[T]>
+where
+    [T; N]: LengthAtMost32,
+{
+    /// Converts a `[T; N]` into a `Box<[T]>`
+    ///
+    /// This conversion moves the array to newly heap-allocated memory.
+    ///
+    /// # Examples
+    /// ```rust
+    /// let boxed: Box<[u8]> = Box::from([4, 2]);
+    /// println!("{:?}", boxed);
+    /// ```
+    fn from(array: [T; N]) -> Box<[T]> {
+        box array
+    }
+}
+
 #[stable(feature = "boxed_slice_try_from", since = "1.43.0")]
 impl<T, const N: usize> TryFrom<Box<[T]>> for Box<[T; N]>
 where

src/libcore/intrinsics.rs

@@ -1314,6 +1314,7 @@ extern "rust-intrinsic" {
     /// The stabilized version of this intrinsic is
     /// [`std::pointer::offset`](../../std/primitive.pointer.html#method.offset).
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     pub fn offset<T>(dst: *const T, offset: isize) -> *const T;
 
     /// Calculates the offset from a pointer, potentially wrapping.
@@ -1331,6 +1332,7 @@ extern "rust-intrinsic" {
     /// The stabilized version of this intrinsic is
     /// [`std::pointer::wrapping_offset`](../../std/primitive.pointer.html#method.wrapping_offset).
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     pub fn arith_offset<T>(dst: *const T, offset: isize) -> *const T;
 
     /// Equivalent to the appropriate `llvm.memcpy.p0i8.0i8.*` intrinsic, with

src/libcore/iter/adapters/mod.rs

@@ -1619,6 +1619,69 @@ impl<I: Iterator> Peekable<I> {
         let iter = &mut self.iter;
         self.peeked.get_or_insert_with(|| iter.next()).as_ref()
     }
+
+    /// Consume the next value of this iterator if a condition is true.
+    ///
+    /// If `func` returns `true` for the next value of this iterator, consume and return it.
+    /// Otherwise, return `None`.
+    ///
+    /// # Examples
+    /// Consume a number if it's equal to 0.
+    /// ```
+    /// #![feature(peekable_next_if)]
+    /// let mut iter = (0..5).peekable();
+    /// // The first item of the iterator is 0; consume it.
+    /// assert_eq!(iter.next_if(|&x| x == 0), Some(0));
+    /// // The next item returned is now 1, so `consume` will return `false`.
+    /// assert_eq!(iter.next_if(|&x| x == 0), None);
+    /// // `next_if` saves the value of the next item if it was not equal to `expected`.
+    /// assert_eq!(iter.next(), Some(1));
+    /// ```
+    ///
+    /// Consume any number less than 10.
+    /// ```
+    /// #![feature(peekable_next_if)]
+    /// let mut iter = (1..20).peekable();
+    /// // Consume all numbers less than 10
+    /// while iter.next_if(|&x| x < 10).is_some() {}
+    /// // The next value returned will be 10
+    /// assert_eq!(iter.next(), Some(10));
+    /// ```
+    #[unstable(feature = "peekable_next_if", issue = "72480")]
+    pub fn next_if(&mut self, func: impl FnOnce(&I::Item) -> bool) -> Option<I::Item> {
+        match self.next() {
+            Some(matched) if func(&matched) => Some(matched),
+            other => {
+                // Since we called `self.next()`, we consumed `self.peeked`.
+                assert!(self.peeked.is_none());
+                self.peeked = Some(other);
+                None
+            }
+        }
+    }
+
+    /// Consume the next item if it is equal to `expected`.
+    ///
+    /// # Example
+    /// Consume a number if it's equal to 0.
+    /// ```
+    /// #![feature(peekable_next_if)]
+    /// let mut iter = (0..5).peekable();
+    /// // The first item of the iterator is 0; consume it.
+    /// assert_eq!(iter.next_if_eq(&0), Some(0));
+    /// // The next item returned is now 1, so `consume` will return `false`.
+    /// assert_eq!(iter.next_if_eq(&0), None);
+    /// // `next_if_eq` saves the value of the next item if it was not equal to `expected`.
+    /// assert_eq!(iter.next(), Some(1));
+    /// ```
+    #[unstable(feature = "peekable_next_if", issue = "72480")]
+    pub fn next_if_eq<R>(&mut self, expected: &R) -> Option<I::Item>
+    where
+        R: ?Sized,
+        I::Item: PartialEq<R>,
+    {
+        self.next_if(|next| next == expected)
+    }
 }
 
 /// An iterator that rejects elements while `predicate` returns `true`.

src/libcore/lib.rs

@@ -85,6 +85,7 @@
 #![feature(const_panic)]
 #![feature(const_fn_union)]
 #![feature(const_generics)]
+#![feature(const_ptr_offset)]
 #![feature(const_ptr_offset_from)]
 #![feature(const_result)]
 #![feature(const_slice_from_raw_parts)]

src/libcore/ptr/const_ptr.rs

@@ -151,8 +151,9 @@ impl<T: ?Sized> *const T {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub unsafe fn offset(self, count: isize) -> *const T
+    pub const unsafe fn offset(self, count: isize) -> *const T
     where
         T: Sized,
     {
@@ -210,8 +211,9 @@ impl<T: ?Sized> *const T {
     /// ```
     #[stable(feature = "ptr_wrapping_offset", since = "1.16.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn wrapping_offset(self, count: isize) -> *const T
+    pub const fn wrapping_offset(self, count: isize) -> *const T
     where
         T: Sized,
     {
@@ -393,8 +395,9 @@ impl<T: ?Sized> *const T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub unsafe fn add(self, count: usize) -> Self
+    pub const unsafe fn add(self, count: usize) -> Self
     where
         T: Sized,
     {
@@ -455,8 +458,9 @@ impl<T: ?Sized> *const T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub unsafe fn sub(self, count: usize) -> Self
+    pub const unsafe fn sub(self, count: usize) -> Self
     where
         T: Sized,
     {
@@ -511,8 +515,9 @@ impl<T: ?Sized> *const T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn wrapping_add(self, count: usize) -> Self
+    pub const fn wrapping_add(self, count: usize) -> Self
     where
         T: Sized,
     {
@@ -567,8 +572,9 @@ impl<T: ?Sized> *const T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn wrapping_sub(self, count: usize) -> Self
+    pub const fn wrapping_sub(self, count: usize) -> Self
     where
         T: Sized,
     {

src/libcore/ptr/mut_ptr.rs

@@ -145,8 +145,9 @@ impl<T: ?Sized> *mut T {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub unsafe fn offset(self, count: isize) -> *mut T
+    pub const unsafe fn offset(self, count: isize) -> *mut T
     where
         T: Sized,
     {
@@ -203,8 +204,9 @@ impl<T: ?Sized> *mut T {
     /// ```
     #[stable(feature = "ptr_wrapping_offset", since = "1.16.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn wrapping_offset(self, count: isize) -> *mut T
+    pub const fn wrapping_offset(self, count: isize) -> *mut T
     where
         T: Sized,
     {
@@ -439,8 +441,9 @@ impl<T: ?Sized> *mut T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub unsafe fn add(self, count: usize) -> Self
+    pub const unsafe fn add(self, count: usize) -> Self
     where
         T: Sized,
     {
@@ -501,8 +504,9 @@ impl<T: ?Sized> *mut T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub unsafe fn sub(self, count: usize) -> Self
+    pub const unsafe fn sub(self, count: usize) -> Self
     where
         T: Sized,
     {
@@ -557,8 +561,9 @@ impl<T: ?Sized> *mut T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn wrapping_add(self, count: usize) -> Self
+    pub const fn wrapping_add(self, count: usize) -> Self
     where
         T: Sized,
     {
@@ -613,8 +618,9 @@ impl<T: ?Sized> *mut T {
     /// ```
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
+    #[rustc_const_unstable(feature = "const_ptr_offset", issue = "71499")]
     #[inline]
-    pub fn wrapping_sub(self, count: usize) -> Self
+    pub const fn wrapping_sub(self, count: usize) -> Self
     where
         T: Sized,
     {

src/libcore/tests/iter.rs

@@ -813,6 +813,30 @@ fn test_iterator_peekable_rfold() {
     assert_eq!(i, xs.len());
 }
 
+#[test]
+fn test_iterator_peekable_next_if_eq() {
+    // first, try on references
+    let xs = vec!["Heart", "of", "Gold"];
+    let mut it = xs.into_iter().peekable();
+    // try before `peek()`
+    assert_eq!(it.next_if_eq(&"trillian"), None);
+    assert_eq!(it.next_if_eq(&"Heart"), Some("Heart"));
+    // try after peek()
+    assert_eq!(it.peek(), Some(&"of"));
+    assert_eq!(it.next_if_eq(&"of"), Some("of"));
+    assert_eq!(it.next_if_eq(&"zaphod"), None);
+    // make sure `next()` still behaves
+    assert_eq!(it.next(), Some("Gold"));
+
+    // make sure comparison works for owned values
+    let xs = vec![String::from("Ludicrous"), "speed".into()];
+    let mut it = xs.into_iter().peekable();
+    // make sure basic functionality works
+    assert_eq!(it.next_if_eq("Ludicrous"), Some("Ludicrous".into()));
+    assert_eq!(it.next_if_eq("speed"), Some("speed".into()));
+    assert_eq!(it.next_if_eq(""), None);
+}
+
 /// This is an iterator that follows the Iterator contract,
 /// but it is not fused. After having returned None once, it will start
 /// producing elements if .next() is called again.

src/libcore/tests/lib.rs

@@ -43,6 +43,7 @@
 #![feature(leading_trailing_ones)]
 #![feature(const_forget)]
 #![feature(option_unwrap_none)]
+#![feature(peekable_next_if)]
 
 extern crate test;
 

src/librustc_codegen_ssa/back/link.rs

@@ -1194,9 +1194,10 @@ fn link_output_kind(sess: &Session, crate_type: CrateType) -> LinkOutputKind {
     };
 
     // Adjust the output kind to target capabilities.
-    let pic_exe_supported = sess.target.target.options.position_independent_executables;
-    let static_pic_exe_supported = false; // FIXME: Add this option to target specs.
-    let static_dylib_supported = sess.target.target.options.crt_static_allows_dylibs;
+    let opts = &sess.target.target.options;
+    let pic_exe_supported = opts.position_independent_executables;
+    let static_pic_exe_supported = opts.static_position_independent_executables;
+    let static_dylib_supported = opts.crt_static_allows_dylibs;
     match kind {
         LinkOutputKind::DynamicPicExe if !pic_exe_supported => LinkOutputKind::DynamicNoPicExe,
         LinkOutputKind::StaticPicExe if !static_pic_exe_supported => LinkOutputKind::StaticNoPicExe,
@@ -1580,16 +1581,7 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
     }
 
     // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER
-    // FIXME: Support `StaticPicExe` correctly.
-    match link_output_kind {
-        LinkOutputKind::DynamicPicExe | LinkOutputKind::StaticPicExe => {
-            cmd.position_independent_executable()
-        }
-        LinkOutputKind::DynamicNoPicExe | LinkOutputKind::StaticNoPicExe => {
-            cmd.no_position_independent_executable()
-        }
-        _ => {}
-    }
+    cmd.set_output_kind(link_output_kind, out_filename);
 
     // OBJECT-FILES-NO, AUDIT-ORDER
     add_relro_args(cmd, sess);
@@ -1618,17 +1610,6 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
         tmpdir,
     );
 
-    // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER
-    // FIXME: Merge with the previous `link_output_kind` match,
-    // and support `StaticPicExe` and `StaticDylib` correctly.
-    match link_output_kind {
-        LinkOutputKind::StaticNoPicExe | LinkOutputKind::StaticPicExe => {
-            cmd.build_static_executable()
-        }
-        LinkOutputKind::DynamicDylib | LinkOutputKind::StaticDylib => cmd.build_dylib(out_filename),
-        _ => {}
-    }
-
     // OBJECT-FILES-NO, AUDIT-ORDER
     if sess.opts.cg.profile_generate.enabled() {
         cmd.pgo_gen();