Merge from rustc

Author: The Miri Cronjob Bot

alloc/src/collections/btree/set.rs

@@ -139,7 +139,7 @@ pub struct Iter<'a, T: 'a> {
 #[stable(feature = "collection_debug", since = "1.17.0")]
 impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_tuple("Iter").field(&self.iter.clone()).finish()
+        f.debug_tuple("Iter").field(&self.iter).finish()
     }
 }
 

alloctests/tests/fmt.rs

@@ -1,6 +1,7 @@
 #![deny(warnings)]
 // FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
 #![allow(static_mut_refs)]
+#![cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
 
 use std::cell::RefCell;
 use std::fmt::{self, Write};

core/src/cell.rs

@@ -549,16 +549,14 @@ impl<T: Copy> Cell<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(cell_update)]
-    ///
     /// use std::cell::Cell;
     ///
     /// let c = Cell::new(5);
     /// c.update(|x| x + 1);
     /// assert_eq!(c.get(), 6);
     /// ```
     #[inline]
-    #[unstable(feature = "cell_update", issue = "50186")]
+    #[stable(feature = "cell_update", since = "CURRENT_RUSTC_VERSION")]
     pub fn update(&self, f: impl FnOnce(T) -> T) {
         let old = self.get();
         self.set(f(old));

core/src/char/convert.rs

@@ -21,6 +21,7 @@ pub(super) const fn from_u32(i: u32) -> Option<char> {
 /// Converts a `u32` to a `char`, ignoring validity. See [`char::from_u32_unchecked`].
 #[inline]
 #[must_use]
+#[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
 pub(super) const unsafe fn from_u32_unchecked(i: u32) -> char {
     // SAFETY: the caller must guarantee that `i` is a valid char value.
     unsafe {
@@ -221,6 +222,7 @@ impl FromStr for char {
 }
 
 #[inline]
+#[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
 const fn char_try_from_u32(i: u32) -> Result<char, CharTryFromError> {
     // This is an optimized version of the check
     // (i > MAX as u32) || (i >= 0xD800 && i <= 0xDFFF),

core/src/intrinsics/mod.rs

@@ -1497,6 +1497,7 @@ pub const fn forget<T: ?Sized>(_: T);
 /// Turning raw bytes (`[u8; SZ]`) into `u32`, `f64`, etc.:
 ///
 /// ```
+/// # #![cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
 /// let raw_bytes = [0x78, 0x56, 0x34, 0x12];
 ///
 /// let num = unsafe {
@@ -2429,35 +2430,35 @@ pub unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> In
 /// Stabilized as [`f16::algebraic_add`], [`f32::algebraic_add`], [`f64::algebraic_add`] and [`f128::algebraic_add`].
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub fn fadd_algebraic<T: Copy>(a: T, b: T) -> T;
+pub const fn fadd_algebraic<T: Copy>(a: T, b: T) -> T;
 
 /// Float subtraction that allows optimizations based on algebraic rules.
 ///
 /// Stabilized as [`f16::algebraic_sub`], [`f32::algebraic_sub`], [`f64::algebraic_sub`] and [`f128::algebraic_sub`].
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub fn fsub_algebraic<T: Copy>(a: T, b: T) -> T;
+pub const fn fsub_algebraic<T: Copy>(a: T, b: T) -> T;
 
 /// Float multiplication that allows optimizations based on algebraic rules.
 ///
 /// Stabilized as [`f16::algebraic_mul`], [`f32::algebraic_mul`], [`f64::algebraic_mul`] and [`f128::algebraic_mul`].
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub fn fmul_algebraic<T: Copy>(a: T, b: T) -> T;
+pub const fn fmul_algebraic<T: Copy>(a: T, b: T) -> T;
 
 /// Float division that allows optimizations based on algebraic rules.
 ///
 /// Stabilized as [`f16::algebraic_div`], [`f32::algebraic_div`], [`f64::algebraic_div`] and [`f128::algebraic_div`].
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub fn fdiv_algebraic<T: Copy>(a: T, b: T) -> T;
+pub const fn fdiv_algebraic<T: Copy>(a: T, b: T) -> T;
 
 /// Float remainder that allows optimizations based on algebraic rules.
 ///
 /// Stabilized as [`f16::algebraic_rem`], [`f32::algebraic_rem`], [`f64::algebraic_rem`] and [`f128::algebraic_rem`].
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub fn frem_algebraic<T: Copy>(a: T, b: T) -> T;
+pub const fn frem_algebraic<T: Copy>(a: T, b: T) -> T;
 
 /// Returns the number of bits set in an integer type `T`
 ///

core/src/num/f128.rs

@@ -197,16 +197,22 @@ impl f128 {
     #[unstable(feature = "f128", issue = "116909")]
     pub const MAX: f128 = 1.18973149535723176508575932662800702e+4932_f128;
 
-    /// One greater than the minimum possible normal power of 2 exponent.
+    /// One greater than the minimum possible *normal* power of 2 exponent
+    /// for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).
     ///
-    /// If <i>x</i>&nbsp;=&nbsp;`MIN_EXP`, then normal numbers
-    /// ≥&nbsp;0.5&nbsp;×&nbsp;2<sup><i>x</i></sup>.
+    /// This corresponds to the exact minimum possible *normal* power of 2 exponent
+    /// for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition).
+    /// In other words, all normal numbers representable by this type are
+    /// greater than or equal to 0.5&nbsp;×&nbsp;2<sup><i>MIN_EXP</i></sup>.
     #[unstable(feature = "f128", issue = "116909")]
     pub const MIN_EXP: i32 = -16_381;
-    /// Maximum possible power of 2 exponent.
+    /// One greater than the maximum possible power of 2 exponent
+    /// for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).
     ///
-    /// If <i>x</i>&nbsp;=&nbsp;`MAX_EXP`, then normal numbers
-    /// &lt;&nbsp;1&nbsp;×&nbsp;2<sup><i>x</i></sup>.
+    /// This corresponds to the exact maximum possible power of 2 exponent
+    /// for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition).
+    /// In other words, all numbers representable by this type are
+    /// strictly less than 2<sup><i>MAX_EXP</i></sup>.
     #[unstable(feature = "f128", issue = "116909")]
     pub const MAX_EXP: i32 = 16_384;
 
@@ -804,7 +810,7 @@ impl f128 {
         }
     }
 
-    /// Calculates the middle point of `self` and `rhs`.
+    /// Calculates the midpoint (average) between `self` and `rhs`.
     ///
     /// This returns NaN when *either* argument is NaN or if a combination of
     /// +inf and -inf is provided as arguments.
@@ -821,6 +827,7 @@ impl f128 {
     /// # }
     /// ```
     #[inline]
+    #[doc(alias = "average")]
     #[unstable(feature = "f128", issue = "116909")]
     #[rustc_const_unstable(feature = "f128", issue = "116909")]
     pub const fn midpoint(self, other: f128) -> f128 {
@@ -903,6 +910,7 @@ impl f128 {
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
+    #[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
     pub const fn to_bits(self) -> u128 {
         // SAFETY: `u128` is a plain old datatype so we can always transmute to it.
         unsafe { mem::transmute(self) }
@@ -950,6 +958,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
+    #[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
     pub const fn from_bits(v: u128) -> Self {
         // It turns out the safety issues with sNaN were overblown! Hooray!
         // SAFETY: `u128` is a plain old datatype so we can always transmute from it.
@@ -1373,8 +1382,9 @@ impl f128 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_add(self, rhs: f128) -> f128 {
+    pub const fn algebraic_add(self, rhs: f128) -> f128 {
         intrinsics::fadd_algebraic(self, rhs)
     }
 
@@ -1383,8 +1393,9 @@ impl f128 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_sub(self, rhs: f128) -> f128 {
+    pub const fn algebraic_sub(self, rhs: f128) -> f128 {
         intrinsics::fsub_algebraic(self, rhs)
     }
 
@@ -1393,8 +1404,9 @@ impl f128 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_mul(self, rhs: f128) -> f128 {
+    pub const fn algebraic_mul(self, rhs: f128) -> f128 {
         intrinsics::fmul_algebraic(self, rhs)
     }
 
@@ -1403,8 +1415,9 @@ impl f128 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_div(self, rhs: f128) -> f128 {
+    pub const fn algebraic_div(self, rhs: f128) -> f128 {
         intrinsics::fdiv_algebraic(self, rhs)
     }
 
@@ -1413,8 +1426,9 @@ impl f128 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_rem(self, rhs: f128) -> f128 {
+    pub const fn algebraic_rem(self, rhs: f128) -> f128 {
         intrinsics::frem_algebraic(self, rhs)
     }
 }

core/src/num/f16.rs

@@ -192,16 +192,22 @@ impl f16 {
     #[unstable(feature = "f16", issue = "116909")]
     pub const MAX: f16 = 6.5504e+4_f16;
 
-    /// One greater than the minimum possible normal power of 2 exponent.
+    /// One greater than the minimum possible *normal* power of 2 exponent
+    /// for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).
     ///
-    /// If <i>x</i>&nbsp;=&nbsp;`MIN_EXP`, then normal numbers
-    /// ≥&nbsp;0.5&nbsp;×&nbsp;2<sup><i>x</i></sup>.
+    /// This corresponds to the exact minimum possible *normal* power of 2 exponent
+    /// for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition).
+    /// In other words, all normal numbers representable by this type are
+    /// greater than or equal to 0.5&nbsp;×&nbsp;2<sup><i>MIN_EXP</i></sup>.
     #[unstable(feature = "f16", issue = "116909")]
     pub const MIN_EXP: i32 = -13;
-    /// Maximum possible power of 2 exponent.
+    /// One greater than the maximum possible power of 2 exponent
+    /// for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).
     ///
-    /// If <i>x</i>&nbsp;=&nbsp;`MAX_EXP`, then normal numbers
-    /// &lt;&nbsp;1&nbsp;×&nbsp;2<sup><i>x</i></sup>.
+    /// This corresponds to the exact maximum possible power of 2 exponent
+    /// for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition).
+    /// In other words, all numbers representable by this type are
+    /// strictly less than 2<sup><i>MAX_EXP</i></sup>.
     #[unstable(feature = "f16", issue = "116909")]
     pub const MAX_EXP: i32 = 16;
 
@@ -792,7 +798,7 @@ impl f16 {
         }
     }
 
-    /// Calculates the middle point of `self` and `rhs`.
+    /// Calculates the midpoint (average) between `self` and `rhs`.
     ///
     /// This returns NaN when *either* argument is NaN or if a combination of
     /// +inf and -inf is provided as arguments.
@@ -808,6 +814,7 @@ impl f16 {
     /// # }
     /// ```
     #[inline]
+    #[doc(alias = "average")]
     #[unstable(feature = "f16", issue = "116909")]
     #[rustc_const_unstable(feature = "f16", issue = "116909")]
     pub const fn midpoint(self, other: f16) -> f16 {
@@ -891,6 +898,7 @@ impl f16 {
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
+    #[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
     pub const fn to_bits(self) -> u16 {
         // SAFETY: `u16` is a plain old datatype so we can always transmute to it.
         unsafe { mem::transmute(self) }
@@ -937,6 +945,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
+    #[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))]
     pub const fn from_bits(v: u16) -> Self {
         // It turns out the safety issues with sNaN were overblown! Hooray!
         // SAFETY: `u16` is a plain old datatype so we can always transmute from it.
@@ -1349,8 +1358,9 @@ impl f16 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_add(self, rhs: f16) -> f16 {
+    pub const fn algebraic_add(self, rhs: f16) -> f16 {
         intrinsics::fadd_algebraic(self, rhs)
     }
 
@@ -1359,8 +1369,9 @@ impl f16 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_sub(self, rhs: f16) -> f16 {
+    pub const fn algebraic_sub(self, rhs: f16) -> f16 {
         intrinsics::fsub_algebraic(self, rhs)
     }
 
@@ -1369,8 +1380,9 @@ impl f16 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_mul(self, rhs: f16) -> f16 {
+    pub const fn algebraic_mul(self, rhs: f16) -> f16 {
         intrinsics::fmul_algebraic(self, rhs)
     }
 
@@ -1379,8 +1391,9 @@ impl f16 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_div(self, rhs: f16) -> f16 {
+    pub const fn algebraic_div(self, rhs: f16) -> f16 {
         intrinsics::fdiv_algebraic(self, rhs)
     }
 
@@ -1389,8 +1402,9 @@ impl f16 {
     /// See [algebraic operators](primitive@f32#algebraic-operators) for more info.
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "float_algebraic", issue = "136469")]
+    #[rustc_const_unstable(feature = "float_algebraic", issue = "136469")]
     #[inline]
-    pub fn algebraic_rem(self, rhs: f16) -> f16 {
+    pub const fn algebraic_rem(self, rhs: f16) -> f16 {
         intrinsics::frem_algebraic(self, rhs)
     }
 }