diff --git a/library/core/src/const_closure.rs b/library/core/src/const_closure.rs
new file mode 100644
index 0000000000000..d2e80e8e7e5df
--- /dev/null
+++ b/library/core/src/const_closure.rs
@@ -0,0 +1,63 @@
+use crate::marker::Destruct;
+
+/// Struct representing a closure with mutably borrowed data.
+///
+/// Example:
+/// ```no_build
+/// #![feature(const_mut_refs)]
+/// use crate::const_closure::ConstFnMutClosure;
+/// const fn imp(state: &mut i32, (arg,): (i32,)) -> i32 {
+///   *state += arg;
+///   *state
+/// }
+/// let mut i = 5;
+/// let mut cl = ConstFnMutClosure::new(&mut i, imp);
+///
+/// assert!(7 == cl(2));
+/// assert!(8 == cl(1));
+/// ```
+pub(crate) struct ConstFnMutClosure<'a, CapturedData: ?Sized, Function> {
+    data: &'a mut CapturedData,
+    func: Function,
+}
+
+impl<'a, CapturedData: ?Sized, Function> ConstFnMutClosure<'a, CapturedData, Function> {
+    /// Function for creating a new closure.
+    ///
+    /// `data` is the a mutable borrow of data that is captured from the environment.
+    ///
+    /// `func` is the function of the closure, it gets the data and a tuple of the arguments closure
+    ///   and return the return value of the closure.
+    pub(crate) const fn new<ClosureArguments, ClosureReturnValue>(
+        data: &'a mut CapturedData,
+        func: Function,
+    ) -> Self
+    where
+        Function: ~const Fn(&mut CapturedData, ClosureArguments) -> ClosureReturnValue,
+    {
+        Self { data, func }
+    }
+}
+
+impl<'a, CapturedData: ?Sized, ClosureArguments, Function, ClosureReturnValue> const
+    FnOnce<ClosureArguments> for ConstFnMutClosure<'a, CapturedData, Function>
+where
+    Function:
+        ~const Fn(&mut CapturedData, ClosureArguments) -> ClosureReturnValue + ~const Destruct,
+{
+    type Output = ClosureReturnValue;
+
+    extern "rust-call" fn call_once(mut self, args: ClosureArguments) -> Self::Output {
+        self.call_mut(args)
+    }
+}
+
+impl<'a, CapturedData: ?Sized, ClosureArguments, Function, ClosureReturnValue> const
+    FnMut<ClosureArguments> for ConstFnMutClosure<'a, CapturedData, Function>
+where
+    Function: ~const Fn(&mut CapturedData, ClosureArguments) -> ClosureReturnValue,
+{
+    extern "rust-call" fn call_mut(&mut self, args: ClosureArguments) -> Self::Output {
+        (self.func)(self.data, args)
+    }
+}
diff --git a/library/core/src/fmt/num.rs b/library/core/src/fmt/num.rs
index 25789d37c2696..d8365ae9bf920 100644
--- a/library/core/src/fmt/num.rs
+++ b/library/core/src/fmt/num.rs
@@ -211,7 +211,7 @@ macro_rules! impl_Display {
         fn $name(mut n: $u, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             // 2^128 is about 3*10^38, so 39 gives an extra byte of space
             let mut buf = [MaybeUninit::<u8>::uninit(); 39];
-            let mut curr = buf.len() as isize;
+            let mut curr = buf.len();
             let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
             let lut_ptr = DEC_DIGITS_LUT.as_ptr();
 
@@ -228,7 +228,7 @@ macro_rules! impl_Display {
 
                 // eagerly decode 4 characters at a time
                 while n >= 10000 {
-                    let rem = (n % 10000) as isize;
+                    let rem = (n % 10000) as usize;
                     n /= 10000;
 
                     let d1 = (rem / 100) << 1;
@@ -238,29 +238,29 @@ macro_rules! impl_Display {
                     // We are allowed to copy to `buf_ptr[curr..curr + 3]` here since
                     // otherwise `curr < 0`. But then `n` was originally at least `10000^10`
                     // which is `10^40 > 2^128 > n`.
-                    ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
-                    ptr::copy_nonoverlapping(lut_ptr.offset(d2), buf_ptr.offset(curr + 2), 2);
+                    ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
+                    ptr::copy_nonoverlapping(lut_ptr.add(d2), buf_ptr.add(curr + 2), 2);
                 }
 
                 // if we reach here numbers are <= 9999, so at most 4 chars long
-                let mut n = n as isize; // possibly reduce 64bit math
+                let mut n = n as usize; // possibly reduce 64bit math
 
                 // decode 2 more chars, if > 2 chars
                 if n >= 100 {
                     let d1 = (n % 100) << 1;
                     n /= 100;
                     curr -= 2;
-                    ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
+                    ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
                 }
 
                 // decode last 1 or 2 chars
                 if n < 10 {
                     curr -= 1;
-                    *buf_ptr.offset(curr) = (n as u8) + b'0';
+                    *buf_ptr.add(curr) = (n as u8) + b'0';
                 } else {
                     let d1 = n << 1;
                     curr -= 2;
-                    ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
+                    ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
                 }
             }
 
@@ -268,7 +268,7 @@ macro_rules! impl_Display {
             // UTF-8 since `DEC_DIGITS_LUT` is
             let buf_slice = unsafe {
                 str::from_utf8_unchecked(
-                    slice::from_raw_parts(buf_ptr.offset(curr), buf.len() - curr as usize))
+                    slice::from_raw_parts(buf_ptr.add(curr), buf.len() - curr))
             };
             f.pad_integral(is_nonnegative, "", buf_slice)
         }
@@ -339,18 +339,18 @@ macro_rules! impl_Exp {
             // Since `curr` always decreases by the number of digits copied, this means
             // that `curr >= 0`.
             let mut buf = [MaybeUninit::<u8>::uninit(); 40];
-            let mut curr = buf.len() as isize; //index for buf
+            let mut curr = buf.len(); //index for buf
             let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
             let lut_ptr = DEC_DIGITS_LUT.as_ptr();
 
             // decode 2 chars at a time
             while n >= 100 {
-                let d1 = ((n % 100) as isize) << 1;
+                let d1 = ((n % 100) as usize) << 1;
                 curr -= 2;
                 // SAFETY: `d1 <= 198`, so we can copy from `lut_ptr[d1..d1 + 2]` since
                 // `DEC_DIGITS_LUT` has a length of 200.
                 unsafe {
-                    ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
+                    ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
                 }
                 n /= 100;
                 exponent += 2;
@@ -362,7 +362,7 @@ macro_rules! impl_Exp {
                 curr -= 1;
                 // SAFETY: Safe since `40 > curr >= 0` (see comment)
                 unsafe {
-                    *buf_ptr.offset(curr) = (n as u8 % 10_u8) + b'0';
+                    *buf_ptr.add(curr) = (n as u8 % 10_u8) + b'0';
                 }
                 n /= 10;
                 exponent += 1;
@@ -372,7 +372,7 @@ macro_rules! impl_Exp {
                 curr -= 1;
                 // SAFETY: Safe since `40 > curr >= 0`
                 unsafe {
-                    *buf_ptr.offset(curr) = b'.';
+                    *buf_ptr.add(curr) = b'.';
                 }
             }
 
@@ -380,10 +380,10 @@ macro_rules! impl_Exp {
             let buf_slice = unsafe {
                 // decode last character
                 curr -= 1;
-                *buf_ptr.offset(curr) = (n as u8) + b'0';
+                *buf_ptr.add(curr) = (n as u8) + b'0';
 
                 let len = buf.len() - curr as usize;
-                slice::from_raw_parts(buf_ptr.offset(curr), len)
+                slice::from_raw_parts(buf_ptr.add(curr), len)
             };
 
             // stores 'e' (or 'E') and the up to 2-digit exponent
@@ -392,13 +392,13 @@ macro_rules! impl_Exp {
             // SAFETY: In either case, `exp_buf` is written within bounds and `exp_ptr[..len]`
             // is contained within `exp_buf` since `len <= 3`.
             let exp_slice = unsafe {
-                *exp_ptr.offset(0) = if upper { b'E' } else { b'e' };
+                *exp_ptr.add(0) = if upper { b'E' } else { b'e' };
                 let len = if exponent < 10 {
-                    *exp_ptr.offset(1) = (exponent as u8) + b'0';
+                    *exp_ptr.add(1) = (exponent as u8) + b'0';
                     2
                 } else {
                     let off = exponent << 1;
-                    ptr::copy_nonoverlapping(lut_ptr.offset(off), exp_ptr.offset(1), 2);
+                    ptr::copy_nonoverlapping(lut_ptr.add(off), exp_ptr.add(1), 2);
                     3
                 };
                 slice::from_raw_parts(exp_ptr, len)
@@ -479,7 +479,7 @@ mod imp {
 impl_Exp!(i128, u128 as u128 via to_u128 named exp_u128);
 
 /// Helper function for writing a u64 into `buf` going from last to first, with `curr`.
-fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], curr: &mut isize) {
+fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], curr: &mut usize) {
     let buf_ptr = MaybeUninit::slice_as_mut_ptr(buf);
     let lut_ptr = DEC_DIGITS_LUT.as_ptr();
     assert!(*curr > 19);
@@ -505,14 +505,14 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu
 
             *curr -= 16;
 
-            ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d3 as isize), buf_ptr.offset(*curr + 4), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d4 as isize), buf_ptr.offset(*curr + 6), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d5 as isize), buf_ptr.offset(*curr + 8), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d6 as isize), buf_ptr.offset(*curr + 10), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d7 as isize), buf_ptr.offset(*curr + 12), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d8 as isize), buf_ptr.offset(*curr + 14), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr + 0), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d2 as usize), buf_ptr.add(*curr + 2), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d3 as usize), buf_ptr.add(*curr + 4), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d4 as usize), buf_ptr.add(*curr + 6), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d5 as usize), buf_ptr.add(*curr + 8), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d6 as usize), buf_ptr.add(*curr + 10), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d7 as usize), buf_ptr.add(*curr + 12), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d8 as usize), buf_ptr.add(*curr + 14), 2);
         }
         if n >= 1e8 as u64 {
             let to_parse = n % 1e8 as u64;
@@ -525,10 +525,10 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu
             let d4 = ((to_parse / 1e0 as u64) % 100) << 1;
             *curr -= 8;
 
-            ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d3 as isize), buf_ptr.offset(*curr + 4), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d4 as isize), buf_ptr.offset(*curr + 6), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr + 0), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d2 as usize), buf_ptr.add(*curr + 2), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d3 as usize), buf_ptr.add(*curr + 4), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d4 as usize), buf_ptr.add(*curr + 6), 2);
         }
         // `n` < 1e8 < (1 << 32)
         let mut n = n as u32;
@@ -540,8 +540,8 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu
             let d2 = (to_parse % 100) << 1;
             *curr -= 4;
 
-            ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2);
-            ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr + 0), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d2 as usize), buf_ptr.add(*curr + 2), 2);
         }
 
         // `n` < 1e4 < (1 << 16)
@@ -550,17 +550,17 @@ fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], cu
             let d1 = (n % 100) << 1;
             n /= 100;
             *curr -= 2;
-            ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr), 2);
         }
 
         // decode last 1 or 2 chars
         if n < 10 {
             *curr -= 1;
-            *buf_ptr.offset(*curr) = (n as u8) + b'0';
+            *buf_ptr.add(*curr) = (n as u8) + b'0';
         } else {
             let d1 = n << 1;
             *curr -= 2;
-            ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr), 2);
+            ptr::copy_nonoverlapping(lut_ptr.add(d1 as usize), buf_ptr.add(*curr), 2);
         }
     }
 }
@@ -593,21 +593,21 @@ impl fmt::Display for i128 {
 fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result {
     // 2^128 is about 3*10^38, so 39 gives an extra byte of space
     let mut buf = [MaybeUninit::<u8>::uninit(); 39];
-    let mut curr = buf.len() as isize;
+    let mut curr = buf.len();
 
     let (n, rem) = udiv_1e19(n);
     parse_u64_into(rem, &mut buf, &mut curr);
 
     if n != 0 {
         // 0 pad up to point
-        let target = (buf.len() - 19) as isize;
+        let target = buf.len() - 19;
         // SAFETY: Guaranteed that we wrote at most 19 bytes, and there must be space
         // remaining since it has length 39
         unsafe {
             ptr::write_bytes(
-                MaybeUninit::slice_as_mut_ptr(&mut buf).offset(target),
+                MaybeUninit::slice_as_mut_ptr(&mut buf).add(target),
                 b'0',
-                (curr - target) as usize,
+                curr - target,
             );
         }
         curr = target;
@@ -616,16 +616,16 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R
         parse_u64_into(rem, &mut buf, &mut curr);
         // Should this following branch be annotated with unlikely?
         if n != 0 {
-            let target = (buf.len() - 38) as isize;
+            let target = buf.len() - 38;
             // The raw `buf_ptr` pointer is only valid until `buf` is used the next time,
             // buf `buf` is not used in this scope so we are good.
             let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
             // SAFETY: At this point we wrote at most 38 bytes, pad up to that point,
             // There can only be at most 1 digit remaining.
             unsafe {
-                ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize);
+                ptr::write_bytes(buf_ptr.add(target), b'0', curr - target);
                 curr = target - 1;
-                *buf_ptr.offset(curr) = (n as u8) + b'0';
+                *buf_ptr.add(curr) = (n as u8) + b'0';
             }
         }
     }
@@ -634,8 +634,8 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R
     // UTF-8 since `DEC_DIGITS_LUT` is
     let buf_slice = unsafe {
         str::from_utf8_unchecked(slice::from_raw_parts(
-            MaybeUninit::slice_as_mut_ptr(&mut buf).offset(curr),
-            buf.len() - curr as usize,
+            MaybeUninit::slice_as_mut_ptr(&mut buf).add(curr),
+            buf.len() - curr,
         ))
     };
     f.pad_integral(is_nonnegative, "", buf_slice)
diff --git a/library/core/src/iter/adapters/array_chunks.rs b/library/core/src/iter/adapters/array_chunks.rs
index 9b479a9f8adfb..489fb13c0dc97 100644
--- a/library/core/src/iter/adapters/array_chunks.rs
+++ b/library/core/src/iter/adapters/array_chunks.rs
@@ -1,4 +1,5 @@
 use crate::array;
+use crate::const_closure::ConstFnMutClosure;
 use crate::iter::{ByRefSized, FusedIterator, Iterator};
 use crate::ops::{ControlFlow, NeverShortCircuit, Try};
 
@@ -82,12 +83,12 @@ where
         }
     }
 
-    fn fold<B, F>(mut self, init: B, f: F) -> B
+    fn fold<B, F>(mut self, init: B, mut f: F) -> B
     where
         Self: Sized,
         F: FnMut(B, Self::Item) -> B,
     {
-        self.try_fold(init, NeverShortCircuit::wrap_mut_2(f)).0
+        self.try_fold(init, ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp)).0
     }
 }
 
@@ -126,12 +127,12 @@ where
         try { acc }
     }
 
-    fn rfold<B, F>(mut self, init: B, f: F) -> B
+    fn rfold<B, F>(mut self, init: B, mut f: F) -> B
     where
         Self: Sized,
         F: FnMut(B, Self::Item) -> B,
     {
-        self.try_rfold(init, NeverShortCircuit::wrap_mut_2(f)).0
+        self.try_rfold(init, ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp)).0
     }
 }
 
diff --git a/library/core/src/iter/adapters/by_ref_sized.rs b/library/core/src/iter/adapters/by_ref_sized.rs
index 477e7117c3ea1..1945e402ff50e 100644
--- a/library/core/src/iter/adapters/by_ref_sized.rs
+++ b/library/core/src/iter/adapters/by_ref_sized.rs
@@ -1,4 +1,7 @@
-use crate::ops::{NeverShortCircuit, Try};
+use crate::{
+    const_closure::ConstFnMutClosure,
+    ops::{NeverShortCircuit, Try},
+};
 
 /// Like `Iterator::by_ref`, but requiring `Sized` so it can forward generics.
 ///
@@ -36,12 +39,13 @@ impl<I: Iterator> Iterator for ByRefSized<'_, I> {
     }
 
     #[inline]
-    fn fold<B, F>(self, init: B, f: F) -> B
+    fn fold<B, F>(self, init: B, mut f: F) -> B
     where
         F: FnMut(B, Self::Item) -> B,
     {
         // `fold` needs ownership, so this can't forward directly.
-        I::try_fold(self.0, init, NeverShortCircuit::wrap_mut_2(f)).0
+        I::try_fold(self.0, init, ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp))
+            .0
     }
 
     #[inline]
@@ -72,12 +76,17 @@ impl<I: DoubleEndedIterator> DoubleEndedIterator for ByRefSized<'_, I> {
     }
 
     #[inline]
-    fn rfold<B, F>(self, init: B, f: F) -> B
+    fn rfold<B, F>(self, init: B, mut f: F) -> B
     where
         F: FnMut(B, Self::Item) -> B,
     {
         // `rfold` needs ownership, so this can't forward directly.
-        I::try_rfold(self.0, init, NeverShortCircuit::wrap_mut_2(f)).0
+        I::try_rfold(
+            self.0,
+            init,
+            ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp),
+        )
+        .0
     }
 
     #[inline]
diff --git a/library/core/src/iter/adapters/mod.rs b/library/core/src/iter/adapters/mod.rs
index bf4fabad32a37..de3a534f81b8a 100644
--- a/library/core/src/iter/adapters/mod.rs
+++ b/library/core/src/iter/adapters/mod.rs
@@ -1,3 +1,4 @@
+use crate::const_closure::ConstFnMutClosure;
 use crate::iter::{InPlaceIterable, Iterator};
 use crate::ops::{ChangeOutputType, ControlFlow, FromResidual, NeverShortCircuit, Residual, Try};
 
@@ -203,12 +204,12 @@ where
             .into_try()
     }
 
-    fn fold<B, F>(mut self, init: B, fold: F) -> B
+    fn fold<B, F>(mut self, init: B, mut fold: F) -> B
     where
         Self: Sized,
         F: FnMut(B, Self::Item) -> B,
     {
-        self.try_fold(init, NeverShortCircuit::wrap_mut_2(fold)).0
+        self.try_fold(init, ConstFnMutClosure::new(&mut fold, NeverShortCircuit::wrap_mut_2_imp)).0
     }
 }
 
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 21775c0a6ab0b..6fbe7ade73255 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -356,6 +356,8 @@ mod bool;
 mod tuple;
 mod unit;
 
+mod const_closure;
+
 #[stable(feature = "core_primitive", since = "1.43.0")]
 pub mod primitive;
 
diff --git a/library/core/src/ops/control_flow.rs b/library/core/src/ops/control_flow.rs
index fd567a8c68492..72ebe653caff3 100644
--- a/library/core/src/ops/control_flow.rs
+++ b/library/core/src/ops/control_flow.rs
@@ -126,7 +126,8 @@ impl<B, C> const ops::FromResidual for ControlFlow<B, C> {
 }
 
 #[unstable(feature = "try_trait_v2_residual", issue = "91285")]
-impl<B, C> ops::Residual<C> for ControlFlow<B, convert::Infallible> {
+#[rustc_const_unstable(feature = "const_try", issue = "74935")]
+impl<B, C> const ops::Residual<C> for ControlFlow<B, convert::Infallible> {
     type TryType = ControlFlow<B, C>;
 }
 
diff --git a/library/core/src/ops/try_trait.rs b/library/core/src/ops/try_trait.rs
index dfde0b37acf43..4d0d4e12adbf8 100644
--- a/library/core/src/ops/try_trait.rs
+++ b/library/core/src/ops/try_trait.rs
@@ -129,7 +129,7 @@ use crate::ops::ControlFlow;
 #[doc(alias = "?")]
 #[lang = "Try"]
 #[const_trait]
-pub trait Try: FromResidual {
+pub trait Try: ~const FromResidual {
     /// The type of the value produced by `?` when *not* short-circuiting.
     #[unstable(feature = "try_trait_v2", issue = "84277")]
     type Output;
@@ -438,10 +438,11 @@ where
 /// and in the other direction,
 /// `<Result<Infallible, E> as Residual<T>>::TryType = Result<T, E>`.
 #[unstable(feature = "try_trait_v2_residual", issue = "91285")]
+#[const_trait]
 pub trait Residual<O> {
     /// The "return" type of this meta-function.
     #[unstable(feature = "try_trait_v2_residual", issue = "91285")]
-    type TryType: Try<Output = O, Residual = Self>;
+    type TryType: ~const Try<Output = O, Residual = Self>;
 }
 
 #[unstable(feature = "pub_crate_should_not_need_unstable_attr", issue = "none")]
@@ -460,14 +461,17 @@ pub(crate) struct NeverShortCircuit<T>(pub T);
 impl<T> NeverShortCircuit<T> {
     /// Wrap a binary `FnMut` to return its result wrapped in a `NeverShortCircuit`.
     #[inline]
-    pub fn wrap_mut_2<A, B>(mut f: impl FnMut(A, B) -> T) -> impl FnMut(A, B) -> Self {
-        move |a, b| NeverShortCircuit(f(a, b))
+    pub const fn wrap_mut_2_imp<A, B, F: ~const FnMut(A, B) -> T>(
+        f: &mut F,
+        (a, b): (A, B),
+    ) -> NeverShortCircuit<T> {
+        NeverShortCircuit(f(a, b))
     }
 }
 
 pub(crate) enum NeverShortCircuitResidual {}
 
-impl<T> Try for NeverShortCircuit<T> {
+impl<T> const Try for NeverShortCircuit<T> {
     type Output = T;
     type Residual = NeverShortCircuitResidual;
 
@@ -482,14 +486,14 @@ impl<T> Try for NeverShortCircuit<T> {
     }
 }
 
-impl<T> FromResidual for NeverShortCircuit<T> {
+impl<T> const FromResidual for NeverShortCircuit<T> {
     #[inline]
     fn from_residual(never: NeverShortCircuitResidual) -> Self {
         match never {}
     }
 }
 
-impl<T> Residual<T> for NeverShortCircuitResidual {
+impl<T> const Residual<T> for NeverShortCircuitResidual {
     type TryType = NeverShortCircuit<T>;
 }
 
diff --git a/library/core/src/option.rs b/library/core/src/option.rs
index 934175863630f..96b16b13256ce 100644
--- a/library/core/src/option.rs
+++ b/library/core/src/option.rs
@@ -2321,7 +2321,8 @@ impl<T> ops::FromResidual<ops::Yeet<()>> for Option<T> {
 }
 
 #[unstable(feature = "try_trait_v2_residual", issue = "91285")]
-impl<T> ops::Residual<T> for Option<convert::Infallible> {
+#[rustc_const_unstable(feature = "const_try", issue = "74935")]
+impl<T> const ops::Residual<T> for Option<convert::Infallible> {
     type TryType = Option<T>;
 }
 
diff --git a/library/core/src/result.rs b/library/core/src/result.rs
index 76eaa191f7811..dc90e90402c8e 100644
--- a/library/core/src/result.rs
+++ b/library/core/src/result.rs
@@ -2116,6 +2116,7 @@ impl<T, E, F: From<E>> ops::FromResidual<ops::Yeet<E>> for Result<T, F> {
 }
 
 #[unstable(feature = "try_trait_v2_residual", issue = "91285")]
-impl<T, E> ops::Residual<T> for Result<convert::Infallible, E> {
+#[rustc_const_unstable(feature = "const_try", issue = "74935")]
+impl<T, E> const ops::Residual<T> for Result<convert::Infallible, E> {
     type TryType = Result<T, E>;
 }
diff --git a/library/core/src/slice/memchr.rs b/library/core/src/slice/memchr.rs
index 7de1f48e6c902..c848c2e18e9b5 100644
--- a/library/core/src/slice/memchr.rs
+++ b/library/core/src/slice/memchr.rs
@@ -141,8 +141,8 @@ pub fn memrchr(x: u8, text: &[u8]) -> Option<usize> {
         // SAFETY: offset starts at len - suffix.len(), as long as it is greater than
         // min_aligned_offset (prefix.len()) the remaining distance is at least 2 * chunk_bytes.
         unsafe {
-            let u = *(ptr.offset(offset as isize - 2 * chunk_bytes as isize) as *const Chunk);
-            let v = *(ptr.offset(offset as isize - chunk_bytes as isize) as *const Chunk);
+            let u = *(ptr.add(offset - 2 * chunk_bytes) as *const Chunk);
+            let v = *(ptr.add(offset - chunk_bytes) as *const Chunk);
 
             // Break if there is a matching byte.
             let zu = contains_zero_byte(u ^ repeated_x);
diff --git a/library/std/src/io/mod.rs b/library/std/src/io/mod.rs
index 01a3873c75cec..90251eb4b02e5 100644
--- a/library/std/src/io/mod.rs
+++ b/library/std/src/io/mod.rs
@@ -265,6 +265,8 @@ pub use self::buffered::WriterPanicked;
 #[unstable(feature = "internal_output_capture", issue = "none")]
 #[doc(no_inline, hidden)]
 pub use self::stdio::set_output_capture;
+#[unstable(feature = "is_terminal", issue = "98070")]
+pub use self::stdio::IsTerminal;
 #[unstable(feature = "print_internals", issue = "none")]
 pub use self::stdio::{_eprint, _print};
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/std/src/io/stdio.rs b/library/std/src/io/stdio.rs
index 2dc12a18a8a66..3c3fa9654bbea 100644
--- a/library/std/src/io/stdio.rs
+++ b/library/std/src/io/stdio.rs
@@ -7,6 +7,7 @@ use crate::io::prelude::*;
 
 use crate::cell::{Cell, RefCell};
 use crate::fmt;
+use crate::fs::File;
 use crate::io::{self, BufReader, IoSlice, IoSliceMut, LineWriter, Lines};
 use crate::sync::atomic::{AtomicBool, Ordering};
 use crate::sync::{Arc, Mutex, MutexGuard, OnceLock};
@@ -1019,6 +1020,34 @@ where
     }
 }
 
+/// Trait to determine if a descriptor/handle refers to a terminal/tty.
+#[unstable(feature = "is_terminal", issue = "98070")]
+pub trait IsTerminal: crate::sealed::Sealed {
+    /// Returns `true` if the descriptor/handle refers to a terminal/tty.
+    ///
+    /// On platforms where Rust does not know how to detect a terminal yet, this will return
+    /// `false`. This will also return `false` if an unexpected error occurred, such as from
+    /// passing an invalid file descriptor.
+    fn is_terminal(&self) -> bool;
+}
+
+macro_rules! impl_is_terminal {
+    ($($t:ty),*$(,)?) => {$(
+        #[unstable(feature = "sealed", issue = "none")]
+        impl crate::sealed::Sealed for $t {}
+
+        #[unstable(feature = "is_terminal", issue = "98070")]
+        impl IsTerminal for $t {
+            #[inline]
+            fn is_terminal(&self) -> bool {
+                crate::sys::io::is_terminal(self)
+            }
+        }
+    )*}
+}
+
+impl_is_terminal!(File, Stdin, StdinLock<'_>, Stdout, StdoutLock<'_>, Stderr, StderrLock<'_>);
+
 #[unstable(
     feature = "print_internals",
     reason = "implementation detail which may disappear or be replaced at any time",
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 3131dd4726984..fd06146d8006f 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -252,6 +252,7 @@
 #![feature(dropck_eyepatch)]
 #![feature(exhaustive_patterns)]
 #![feature(intra_doc_pointers)]
+#![feature(is_terminal)]
 #![cfg_attr(bootstrap, feature(label_break_value))]
 #![feature(lang_items)]
 #![feature(let_chains)]
diff --git a/library/std/src/os/fd/owned.rs b/library/std/src/os/fd/owned.rs
index 71e33fb9ed864..8c44415190748 100644
--- a/library/std/src/os/fd/owned.rs
+++ b/library/std/src/os/fd/owned.rs
@@ -192,6 +192,23 @@ impl fmt::Debug for OwnedFd {
     }
 }
 
+macro_rules! impl_is_terminal {
+    ($($t:ty),*$(,)?) => {$(
+        #[unstable(feature = "sealed", issue = "none")]
+        impl crate::sealed::Sealed for $t {}
+
+        #[unstable(feature = "is_terminal", issue = "98070")]
+        impl crate::io::IsTerminal for $t {
+            #[inline]
+            fn is_terminal(&self) -> bool {
+                crate::sys::io::is_terminal(self)
+            }
+        }
+    )*}
+}
+
+impl_is_terminal!(BorrowedFd<'_>, OwnedFd);
+
 /// A trait to borrow the file descriptor from an underlying object.
 ///
 /// This is only available on unix platforms and must be imported in order to
diff --git a/library/std/src/os/mod.rs b/library/std/src/os/mod.rs
index 18c64b5100764..380950b0ac37f 100644
--- a/library/std/src/os/mod.rs
+++ b/library/std/src/os/mod.rs
@@ -147,7 +147,7 @@ pub mod solid;
 pub mod vxworks;
 
 #[cfg(any(unix, target_os = "wasi", doc))]
-mod fd;
+pub(crate) mod fd;
 
 #[cfg(any(target_os = "linux", target_os = "android", doc))]
 mod net;
diff --git a/library/std/src/os/windows/io/handle.rs b/library/std/src/os/windows/io/handle.rs
index 16cc8fa2783ee..1dfecc57338a7 100644
--- a/library/std/src/os/windows/io/handle.rs
+++ b/library/std/src/os/windows/io/handle.rs
@@ -384,6 +384,23 @@ impl fmt::Debug for OwnedHandle {
     }
 }
 
+macro_rules! impl_is_terminal {
+    ($($t:ty),*$(,)?) => {$(
+        #[unstable(feature = "sealed", issue = "none")]
+        impl crate::sealed::Sealed for $t {}
+
+        #[unstable(feature = "is_terminal", issue = "98070")]
+        impl crate::io::IsTerminal for $t {
+            #[inline]
+            fn is_terminal(&self) -> bool {
+                crate::sys::io::is_terminal(self)
+            }
+        }
+    )*}
+}
+
+impl_is_terminal!(BorrowedHandle<'_>, OwnedHandle);
+
 /// A trait to borrow the handle from an underlying object.
 #[stable(feature = "io_safety", since = "1.63.0")]
 pub trait AsHandle {
diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs
index 38dcf6cbf7db7..4b07b393a2f5a 100644
--- a/library/std/src/panicking.rs
+++ b/library/std/src/panicking.rs
@@ -300,7 +300,7 @@ pub mod panic_count {
     thread_local! { static LOCAL_PANIC_COUNT: Cell<usize> = const { Cell::new(0) } }
 
     // Sum of panic counts from all threads. The purpose of this is to have
-    // a fast path in `is_zero` (which is used by `panicking`). In any particular
+    // a fast path in `count_is_zero` (which is used by `panicking`). In any particular
     // thread, if that thread currently views `GLOBAL_PANIC_COUNT` as being zero,
     // then `LOCAL_PANIC_COUNT` in that thread is zero. This invariant holds before
     // and after increase and decrease, but not necessarily during their execution.
@@ -369,7 +369,7 @@ pub mod panic_count {
     }
 
     // Slow path is in a separate function to reduce the amount of code
-    // inlined from `is_zero`.
+    // inlined from `count_is_zero`.
     #[inline(never)]
     #[cold]
     fn is_zero_slow_path() -> bool {
diff --git a/library/std/src/sys/sgx/abi/usercalls/alloc.rs b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
index 5409bd1777c2a..0d934318c22a4 100644
--- a/library/std/src/sys/sgx/abi/usercalls/alloc.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
@@ -316,9 +316,9 @@ where
 //   | small1 | Chunk smaller than 8 bytes
 //   +--------+
 fn region_as_aligned_chunks(ptr: *const u8, len: usize) -> (usize, usize, usize) {
-    let small0_size = if ptr as usize % 8 == 0 { 0 } else { 8 - ptr as usize % 8 };
-    let small1_size = (len - small0_size as usize) % 8;
-    let big_size = len - small0_size as usize - small1_size as usize;
+    let small0_size = if ptr.is_aligned_to(8) { 0 } else { 8 - ptr.addr() % 8 };
+    let small1_size = (len - small0_size) % 8;
+    let big_size = len - small0_size - small1_size;
 
     (small0_size, big_size, small1_size)
 }
@@ -364,8 +364,8 @@ pub(crate) unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize)
                     mfence
                     lfence
                     ",
-                    val = in(reg_byte) *src.offset(off as isize),
-                    dst = in(reg) dst.offset(off as isize),
+                    val = in(reg_byte) *src.add(off),
+                    dst = in(reg) dst.add(off),
                     seg_sel = in(reg) &mut seg_sel,
                     options(nostack, att_syntax)
                 );
@@ -378,8 +378,8 @@ pub(crate) unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize)
     assert!(is_enclave_range(src, len));
     assert!(is_user_range(dst, len));
     assert!(len < isize::MAX as usize);
-    assert!(!(src as usize).overflowing_add(len).1);
-    assert!(!(dst as usize).overflowing_add(len).1);
+    assert!(!src.addr().overflowing_add(len).1);
+    assert!(!dst.addr().overflowing_add(len).1);
 
     if len < 8 {
         // Can't align on 8 byte boundary: copy safely byte per byte
@@ -404,17 +404,17 @@ pub(crate) unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize)
 
         unsafe {
             // Copy small0
-            copy_bytewise_to_userspace(src, dst, small0_size as _);
+            copy_bytewise_to_userspace(src, dst, small0_size);
 
             // Copy big
-            let big_src = src.offset(small0_size as _);
-            let big_dst = dst.offset(small0_size as _);
-            copy_quadwords(big_src as _, big_dst, big_size);
+            let big_src = src.add(small0_size);
+            let big_dst = dst.add(small0_size);
+            copy_quadwords(big_src, big_dst, big_size);
 
             // Copy small1
-            let small1_src = src.offset(big_size as isize + small0_size as isize);
-            let small1_dst = dst.offset(big_size as isize + small0_size as isize);
-            copy_bytewise_to_userspace(small1_src, small1_dst, small1_size as _);
+            let small1_src = src.add(big_size + small0_size);
+            let small1_dst = dst.add(big_size + small0_size);
+            copy_bytewise_to_userspace(small1_src, small1_dst, small1_size);
         }
     }
 }
diff --git a/library/std/src/sys/unix/io.rs b/library/std/src/sys/unix/io.rs
index deb5ee76bd035..8d189059d3641 100644
--- a/library/std/src/sys/unix/io.rs
+++ b/library/std/src/sys/unix/io.rs
@@ -1,4 +1,6 @@
 use crate::marker::PhantomData;
+use crate::os::fd::owned::AsFd;
+use crate::os::fd::raw::AsRawFd;
 use crate::slice;
 
 use libc::{c_void, iovec};
@@ -74,3 +76,8 @@ impl<'a> IoSliceMut<'a> {
         unsafe { slice::from_raw_parts_mut(self.vec.iov_base as *mut u8, self.vec.iov_len) }
     }
 }
+
+pub fn is_terminal(fd: &impl AsFd) -> bool {
+    let fd = fd.as_fd();
+    unsafe { libc::isatty(fd.as_raw_fd()) != 0 }
+}
diff --git a/library/std/src/sys/unsupported/io.rs b/library/std/src/sys/unsupported/io.rs
index d5f475b4310fd..82610ffab7e1e 100644
--- a/library/std/src/sys/unsupported/io.rs
+++ b/library/std/src/sys/unsupported/io.rs
@@ -45,3 +45,7 @@ impl<'a> IoSliceMut<'a> {
         self.0
     }
 }
+
+pub fn is_terminal<T>(_: &T) -> bool {
+    false
+}
diff --git a/library/std/src/sys/wasi/io.rs b/library/std/src/sys/wasi/io.rs
index ee017d13a4ca0..bd9f8872333e2 100644
--- a/library/std/src/sys/wasi/io.rs
+++ b/library/std/src/sys/wasi/io.rs
@@ -1,6 +1,8 @@
 #![deny(unsafe_op_in_unsafe_fn)]
 
 use crate::marker::PhantomData;
+use crate::os::fd::owned::AsFd;
+use crate::os::fd::raw::AsRawFd;
 use crate::slice;
 
 #[derive(Copy, Clone)]
@@ -71,3 +73,8 @@ impl<'a> IoSliceMut<'a> {
         unsafe { slice::from_raw_parts_mut(self.vec.buf as *mut u8, self.vec.buf_len) }
     }
 }
+
+pub fn is_terminal(fd: &impl AsFd) -> bool {
+    let fd = fd.as_fd();
+    unsafe { libc::isatty(fd.as_raw_fd()) != 0 }
+}
diff --git a/library/std/src/sys/windows/c.rs b/library/std/src/sys/windows/c.rs
index 89d0ab59be89f..3f59abb5b0ec3 100644
--- a/library/std/src/sys/windows/c.rs
+++ b/library/std/src/sys/windows/c.rs
@@ -126,6 +126,8 @@ pub const SECURITY_SQOS_PRESENT: DWORD = 0x00100000;
 
 pub const FIONBIO: c_ulong = 0x8004667e;
 
+pub const MAX_PATH: usize = 260;
+
 #[repr(C)]
 #[derive(Copy)]
 pub struct WIN32_FIND_DATAW {
@@ -279,7 +281,6 @@ pub const STATUS_INVALID_PARAMETER: NTSTATUS = 0xc000000d_u32 as _;
 pub const STATUS_PENDING: NTSTATUS = 0x103 as _;
 pub const STATUS_END_OF_FILE: NTSTATUS = 0xC0000011_u32 as _;
 pub const STATUS_NOT_IMPLEMENTED: NTSTATUS = 0xC0000002_u32 as _;
-pub const STATUS_NOT_SUPPORTED: NTSTATUS = 0xC00000BB_u32 as _;
 
 // Equivalent to the `NT_SUCCESS` C preprocessor macro.
 // See: https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/using-ntstatus-values
@@ -289,6 +290,7 @@ pub fn nt_success(status: NTSTATUS) -> bool {
 
 // "RNG\0"
 pub const BCRYPT_RNG_ALGORITHM: &[u16] = &[b'R' as u16, b'N' as u16, b'G' as u16, 0];
+pub const BCRYPT_USE_SYSTEM_PREFERRED_RNG: DWORD = 0x00000002;
 
 #[repr(C)]
 pub struct UNICODE_STRING {
@@ -534,6 +536,12 @@ pub struct SYMBOLIC_LINK_REPARSE_BUFFER {
 
 /// NB: Use carefully! In general using this as a reference is likely to get the
 /// provenance wrong for the `PathBuffer` field!
+#[repr(C)]
+pub struct FILE_NAME_INFO {
+    pub FileNameLength: DWORD,
+    pub FileName: [WCHAR; 1],
+}
+
 #[repr(C)]
 pub struct MOUNT_POINT_REPARSE_BUFFER {
     pub SubstituteNameOffset: c_ushort,
@@ -817,10 +825,6 @@ if #[cfg(not(target_vendor = "uwp"))] {
 
     #[link(name = "advapi32")]
     extern "system" {
-        // Forbidden when targeting UWP
-        #[link_name = "SystemFunction036"]
-        pub fn RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: ULONG) -> BOOLEAN;
-
         // Allowed but unused by UWP
         pub fn OpenProcessToken(
             ProcessHandle: HANDLE,
diff --git a/library/std/src/sys/windows/io.rs b/library/std/src/sys/windows/io.rs
index fb06df1f80cda..0879ef199338e 100644
--- a/library/std/src/sys/windows/io.rs
+++ b/library/std/src/sys/windows/io.rs
@@ -1,6 +1,10 @@
 use crate::marker::PhantomData;
+use crate::mem::size_of;
+use crate::os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle};
 use crate::slice;
-use crate::sys::c;
+use crate::sys::{c, Align8};
+use core;
+use libc;
 
 #[derive(Copy, Clone)]
 #[repr(transparent)]
@@ -78,3 +82,66 @@ impl<'a> IoSliceMut<'a> {
         unsafe { slice::from_raw_parts_mut(self.vec.buf as *mut u8, self.vec.len as usize) }
     }
 }
+
+pub fn is_terminal(h: &impl AsHandle) -> bool {
+    unsafe { handle_is_console(h.as_handle()) }
+}
+
+unsafe fn handle_is_console(handle: BorrowedHandle<'_>) -> bool {
+    let handle = handle.as_raw_handle();
+
+    // A null handle means the process has no console.
+    if handle.is_null() {
+        return false;
+    }
+
+    let mut out = 0;
+    if c::GetConsoleMode(handle, &mut out) != 0 {
+        // False positives aren't possible. If we got a console then we definitely have a console.
+        return true;
+    }
+
+    // At this point, we *could* have a false negative. We can determine that this is a true
+    // negative if we can detect the presence of a console on any of the standard I/O streams. If
+    // another stream has a console, then we know we're in a Windows console and can therefore
+    // trust the negative.
+    for std_handle in [c::STD_INPUT_HANDLE, c::STD_OUTPUT_HANDLE, c::STD_ERROR_HANDLE] {
+        let std_handle = c::GetStdHandle(std_handle);
+        if !std_handle.is_null()
+            && std_handle != handle
+            && c::GetConsoleMode(std_handle, &mut out) != 0
+        {
+            return false;
+        }
+    }
+
+    // Otherwise, we fall back to an msys hack to see if we can detect the presence of a pty.
+    msys_tty_on(handle)
+}
+
+unsafe fn msys_tty_on(handle: c::HANDLE) -> bool {
+    const SIZE: usize = size_of::<c::FILE_NAME_INFO>() + c::MAX_PATH * size_of::<c::WCHAR>();
+    let mut name_info_bytes = Align8([0u8; SIZE]);
+    let res = c::GetFileInformationByHandleEx(
+        handle,
+        c::FileNameInfo,
+        name_info_bytes.0.as_mut_ptr() as *mut libc::c_void,
+        SIZE as u32,
+    );
+    if res == 0 {
+        return false;
+    }
+    let name_info: &c::FILE_NAME_INFO = &*(name_info_bytes.0.as_ptr() as *const c::FILE_NAME_INFO);
+    let name_len = name_info.FileNameLength as usize / 2;
+    // Offset to get the `FileName` field.
+    let name_ptr = name_info_bytes.0.as_ptr().offset(size_of::<c::DWORD>() as isize).cast::<u16>();
+    let s = core::slice::from_raw_parts(name_ptr, name_len);
+    let name = String::from_utf16_lossy(s);
+    // This checks whether 'pty' exists in the file name, which indicates that
+    // a pseudo-terminal is attached. To mitigate against false positives
+    // (e.g., an actual file name that contains 'pty'), we also require that
+    // either the strings 'msys-' or 'cygwin-' are in the file name as well.)
+    let is_msys = name.contains("msys-") || name.contains("cygwin-");
+    let is_pty = name.contains("-pty");
+    is_msys && is_pty
+}
diff --git a/library/std/src/sys/windows/rand.rs b/library/std/src/sys/windows/rand.rs
index d6cd8f8027162..b5a49489d3fb8 100644
--- a/library/std/src/sys/windows/rand.rs
+++ b/library/std/src/sys/windows/rand.rs
@@ -13,15 +13,12 @@
 //! but significant number of users to experience panics caused by a failure of
 //! this function. See [#94098].
 //!
-//! The current version changes this to use the `BCRYPT_RNG_ALG_HANDLE`
-//! [Pseudo-handle], which gets the default RNG algorithm without querying the
-//! system preference thus hopefully avoiding the previous issue.
-//! This is only supported on Windows 10+ so a fallback is used for older versions.
+//! The current version falls back to using `BCryptOpenAlgorithmProvider` if
+//! `BCRYPT_USE_SYSTEM_PREFERRED_RNG` fails for any reason.
 //!
 //! [#94098]: https://github.com/rust-lang/rust/issues/94098
 //! [`RtlGenRandom`]: https://docs.microsoft.com/en-us/windows/win32/api/ntsecapi/nf-ntsecapi-rtlgenrandom
 //! [`BCryptGenRandom`]: https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom
-//! [Pseudo-handle]: https://docs.microsoft.com/en-us/windows/win32/seccng/cng-algorithm-pseudo-handles
 use crate::mem;
 use crate::ptr;
 use crate::sys::c;
@@ -33,37 +30,35 @@ use crate::sys::c;
 /// [`HashMap`]: crate::collections::HashMap
 /// [`RandomState`]: crate::collections::hash_map::RandomState
 pub fn hashmap_random_keys() -> (u64, u64) {
-    Rng::open().and_then(|rng| rng.gen_random_keys()).unwrap_or_else(fallback_rng)
+    Rng::SYSTEM.gen_random_keys().unwrap_or_else(fallback_rng)
 }
 
-struct Rng(c::BCRYPT_ALG_HANDLE);
+struct Rng {
+    algorithm: c::BCRYPT_ALG_HANDLE,
+    flags: u32,
+}
 impl Rng {
-    #[cfg(miri)]
-    fn open() -> Result<Self, c::NTSTATUS> {
-        const BCRYPT_RNG_ALG_HANDLE: c::BCRYPT_ALG_HANDLE = ptr::invalid_mut(0x81);
-        let _ = (
-            c::BCryptOpenAlgorithmProvider,
-            c::BCryptCloseAlgorithmProvider,
-            c::BCRYPT_RNG_ALGORITHM,
-            c::STATUS_NOT_SUPPORTED,
-        );
-        Ok(Self(BCRYPT_RNG_ALG_HANDLE))
+    const SYSTEM: Self = unsafe { Self::new(ptr::null_mut(), c::BCRYPT_USE_SYSTEM_PREFERRED_RNG) };
+
+    /// Create the RNG from an existing algorithm handle.
+    ///
+    /// # Safety
+    ///
+    /// The handle must either be null or a valid algorithm handle.
+    const unsafe fn new(algorithm: c::BCRYPT_ALG_HANDLE, flags: u32) -> Self {
+        Self { algorithm, flags }
     }
-    #[cfg(not(miri))]
-    // Open a handle to the RNG algorithm.
+
+    /// Open a handle to the RNG algorithm.
     fn open() -> Result<Self, c::NTSTATUS> {
         use crate::sync::atomic::AtomicPtr;
         use crate::sync::atomic::Ordering::{Acquire, Release};
-        const ERROR_VALUE: c::LPVOID = ptr::invalid_mut(usize::MAX);
 
         // An atomic is used so we don't need to reopen the handle every time.
         static HANDLE: AtomicPtr<crate::ffi::c_void> = AtomicPtr::new(ptr::null_mut());
 
         let mut handle = HANDLE.load(Acquire);
-        // We use a sentinel value to designate an error occurred last time.
-        if handle == ERROR_VALUE {
-            Err(c::STATUS_NOT_SUPPORTED)
-        } else if handle.is_null() {
+        if handle.is_null() {
             let status = unsafe {
                 c::BCryptOpenAlgorithmProvider(
                     &mut handle,
@@ -80,13 +75,12 @@ impl Rng {
                     unsafe { c::BCryptCloseAlgorithmProvider(handle, 0) };
                     handle = previous_handle;
                 }
-                Ok(Self(handle))
+                Ok(unsafe { Self::new(handle, 0) })
             } else {
-                HANDLE.store(ERROR_VALUE, Release);
                 Err(status)
             }
         } else {
-            Ok(Self(handle))
+            Ok(unsafe { Self::new(handle, 0) })
         }
     }
 
@@ -94,33 +88,19 @@ impl Rng {
         let mut v = (0, 0);
         let status = unsafe {
             let size = mem::size_of_val(&v).try_into().unwrap();
-            c::BCryptGenRandom(self.0, ptr::addr_of_mut!(v).cast(), size, 0)
+            c::BCryptGenRandom(self.algorithm, ptr::addr_of_mut!(v).cast(), size, self.flags)
         };
         if c::nt_success(status) { Ok(v) } else { Err(status) }
     }
 }
 
-/// Generate random numbers using the fallback RNG function (RtlGenRandom)
-#[cfg(not(target_vendor = "uwp"))]
+/// Generate random numbers using the fallback RNG function
 #[inline(never)]
 fn fallback_rng(rng_status: c::NTSTATUS) -> (u64, u64) {
-    let mut v = (0, 0);
-    let ret =
-        unsafe { c::RtlGenRandom(&mut v as *mut _ as *mut u8, mem::size_of_val(&v) as c::ULONG) };
-
-    if ret != 0 {
-        v
-    } else {
-        panic!(
-            "RNG broken: {rng_status:#x}, fallback RNG broken: {}",
-            crate::io::Error::last_os_error()
-        )
+    match Rng::open().and_then(|rng| rng.gen_random_keys()) {
+        Ok(keys) => keys,
+        Err(status) => {
+            panic!("RNG broken: {rng_status:#x}, fallback RNG broken: {status:#x}")
+        }
     }
 }
-
-/// We can't use RtlGenRandom with UWP, so there is no fallback
-#[cfg(target_vendor = "uwp")]
-#[inline(never)]
-fn fallback_rng(rng_status: c::NTSTATUS) -> (u64, u64) {
-    panic!("RNG broken: {rng_status:#x} fallback RNG broken: RtlGenRandom() not supported on UWP");
-}
diff --git a/library/test/src/cli.rs b/library/test/src/cli.rs
index f981b9c495476..8be32183fe780 100644
--- a/library/test/src/cli.rs
+++ b/library/test/src/cli.rs
@@ -3,9 +3,9 @@
 use std::env;
 use std::path::PathBuf;
 
-use super::helpers::isatty;
 use super::options::{ColorConfig, Options, OutputFormat, RunIgnored};
 use super::time::TestTimeOptions;
+use std::io::{self, IsTerminal};
 
 #[derive(Debug)]
 pub struct TestOpts {
@@ -32,7 +32,7 @@ pub struct TestOpts {
 impl TestOpts {
     pub fn use_color(&self) -> bool {
         match self.color {
-            ColorConfig::AutoColor => !self.nocapture && isatty::stdout_isatty(),
+            ColorConfig::AutoColor => !self.nocapture && io::stdout().is_terminal(),
             ColorConfig::AlwaysColor => true,
             ColorConfig::NeverColor => false,
         }
diff --git a/library/test/src/helpers/isatty.rs b/library/test/src/helpers/isatty.rs
deleted file mode 100644
index 874ecc3764572..0000000000000
--- a/library/test/src/helpers/isatty.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-//! Helper module which provides a function to test
-//! if stdout is a tty.
-
-cfg_if::cfg_if! {
-    if #[cfg(unix)] {
-        pub fn stdout_isatty() -> bool {
-            unsafe { libc::isatty(libc::STDOUT_FILENO) != 0 }
-        }
-    } else if #[cfg(windows)] {
-        pub fn stdout_isatty() -> bool {
-            type DWORD = u32;
-            type BOOL = i32;
-            type HANDLE = *mut u8;
-            type LPDWORD = *mut u32;
-            const STD_OUTPUT_HANDLE: DWORD = -11i32 as DWORD;
-            extern "system" {
-                fn GetStdHandle(which: DWORD) -> HANDLE;
-                fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: LPDWORD) -> BOOL;
-            }
-            unsafe {
-                let handle = GetStdHandle(STD_OUTPUT_HANDLE);
-                let mut out = 0;
-                GetConsoleMode(handle, &mut out) != 0
-            }
-        }
-    } else {
-        // FIXME: Implement isatty on SGX
-        pub fn stdout_isatty() -> bool {
-            false
-        }
-    }
-}
diff --git a/library/test/src/helpers/mod.rs b/library/test/src/helpers/mod.rs
index 049cadf86a6d0..6f366a911e8cd 100644
--- a/library/test/src/helpers/mod.rs
+++ b/library/test/src/helpers/mod.rs
@@ -3,6 +3,5 @@
 
 pub mod concurrency;
 pub mod exit_code;
-pub mod isatty;
 pub mod metrics;
 pub mod shuffle;
diff --git a/library/test/src/lib.rs b/library/test/src/lib.rs
index 3b7193adcc758..f595e2a74d4ad 100644
--- a/library/test/src/lib.rs
+++ b/library/test/src/lib.rs
@@ -17,6 +17,7 @@
 #![doc(test(attr(deny(warnings))))]
 #![feature(bench_black_box)]
 #![feature(internal_output_capture)]
+#![feature(is_terminal)]
 #![feature(staged_api)]
 #![feature(process_exitcode_internals)]
 #![feature(test)]
diff --git a/src/doc/rustc/src/SUMMARY.md b/src/doc/rustc/src/SUMMARY.md
index 4fbfd3a4cec79..06883ddd58bcf 100644
--- a/src/doc/rustc/src/SUMMARY.md
+++ b/src/doc/rustc/src/SUMMARY.md
@@ -24,6 +24,7 @@
     - [armv6k-nintendo-3ds](platform-support/armv6k-nintendo-3ds.md)
     - [armv7-unknown-linux-uclibceabi](platform-support/armv7-unknown-linux-uclibceabi.md)
     - [armv7-unknown-linux-uclibceabihf](platform-support/armv7-unknown-linux-uclibceabihf.md)
+    - [\*-android and \*-androideabi](platform-support/android.md)
     - [\*-fuchsia](platform-support/fuchsia.md)
     - [\*-kmc-solid_\*](platform-support/kmc-solid.md)
     - [m68k-unknown-linux-gnu](platform-support/m68k-unknown-linux-gnu.md)
diff --git a/src/doc/rustc/src/command-line-arguments.md b/src/doc/rustc/src/command-line-arguments.md
index f05ff3f1b6b4e..79cdfb82e417e 100644
--- a/src/doc/rustc/src/command-line-arguments.md
+++ b/src/doc/rustc/src/command-line-arguments.md
@@ -270,6 +270,11 @@ This flag will set which lints should be set to the [warn level](lints/levels.md
 
 _Note:_ The order of these lint level arguments is taken into account, see [lint level via compiler flag](lints/levels.md#via-compiler-flag) for more information.
 
+<a id="option-force-warn"></a>
+## `--force-warn`: force a lint to warn
+
+This flag sets the given lint to the [forced warn level](lints/levels.md#force-warn) and the level cannot be overridden, even ignoring the [lint caps](lints/levels.md#capping-lints).
+
 <a id="option-a-allow"></a>
 ## `-A`: set lint allowed
 
@@ -381,6 +386,12 @@ are:
 - `always` — Always use colors.
 - `never` — Never colorize output.
 
+<a id="option-diagnostic-width"></a>
+## `--diagnostic-width`: specify the terminal width for diagnostics
+
+This flag takes a number that specifies the width of the terminal in characters.
+Formatting of diagnostics will take the width into consideration to make them better fit on the screen.
+
 <a id="option-remap-path-prefix"></a>
 ## `--remap-path-prefix`: remap source names in output
 
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 37b530dcb06cf..ea2792c218bbf 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -125,17 +125,17 @@ target | std | notes
 `aarch64-apple-ios` | ✓ | ARM64 iOS
 [`aarch64-apple-ios-sim`](platform-support/aarch64-apple-ios-sim.md) | ✓ | Apple iOS Simulator on ARM64
 `aarch64-fuchsia` | ✓ | ARM64 Fuchsia
-`aarch64-linux-android` | ✓ | ARM64 Android
+[`aarch64-linux-android`](platform-support/android.md) | ✓ | ARM64 Android
 `aarch64-unknown-none-softfloat` | * | Bare ARM64, softfloat
 `aarch64-unknown-none` | * | Bare ARM64, hardfloat
-`arm-linux-androideabi` | ✓ | ARMv7 Android
+[`arm-linux-androideabi`](platform-support/android.md) | ✓ | ARMv7 Android
 `arm-unknown-linux-musleabi` | ✓ | ARMv6 Linux with MUSL
 `arm-unknown-linux-musleabihf` | ✓ | ARMv6 Linux with MUSL, hardfloat
 `armebv7r-none-eabi` | * | Bare ARMv7-R, Big Endian
 `armebv7r-none-eabihf` | * | Bare ARMv7-R, Big Endian, hardfloat
 `armv5te-unknown-linux-gnueabi` | ✓ | ARMv5TE Linux (kernel 4.4, glibc 2.23)
 `armv5te-unknown-linux-musleabi` | ✓ | ARMv5TE Linux with MUSL
-`armv7-linux-androideabi` | ✓ | ARMv7a Android
+[`armv7-linux-androideabi`](platform-support/android.md) | ✓ | ARMv7a Android
 `armv7-unknown-linux-gnueabi` | ✓ |ARMv7 Linux (kernel 4.15, glibc 2.27)
 `armv7-unknown-linux-musleabi` | ✓ |ARMv7 Linux with MUSL
 `armv7-unknown-linux-musleabihf` | ✓ | ARMv7 Linux with MUSL, hardfloat
@@ -146,7 +146,7 @@ target | std | notes
 `i586-pc-windows-msvc` | * | 32-bit Windows w/o SSE
 `i586-unknown-linux-gnu` | ✓ | 32-bit Linux w/o SSE (kernel 4.4, glibc 2.23)
 `i586-unknown-linux-musl` | ✓ | 32-bit Linux w/o SSE, MUSL
-`i686-linux-android` | ✓ | 32-bit x86 Android
+[`i686-linux-android`](platform-support/android.md) | ✓ | 32-bit x86 Android
 `i686-unknown-freebsd` | ✓ | 32-bit FreeBSD
 `i686-unknown-linux-musl` | ✓ | 32-bit Linux with MUSL
 `mips-unknown-linux-musl` | ✓ | MIPS Linux with MUSL
@@ -165,7 +165,7 @@ target | std | notes
 `thumbv7em-none-eabi` | * | Bare Cortex-M4, M7
 `thumbv7em-none-eabihf` | * | Bare Cortex-M4F, M7F, FPU, hardfloat
 `thumbv7m-none-eabi` | * | Bare Cortex-M3
-`thumbv7neon-linux-androideabi` | ✓ | Thumb2-mode ARMv7a Android with NEON
+[`thumbv7neon-linux-androideabi`](platform-support/android.md) | ✓ | Thumb2-mode ARMv7a Android with NEON
 `thumbv7neon-unknown-linux-gnueabihf` | ✓ | Thumb2-mode ARMv7a Linux with NEON (kernel 4.4, glibc 2.23)
 `thumbv8m.base-none-eabi` | * | ARMv8-M Baseline
 `thumbv8m.main-none-eabi` | * | ARMv8-M Mainline
@@ -176,7 +176,7 @@ target | std | notes
 `x86_64-apple-ios` | ✓ | 64-bit x86 iOS
 [`x86_64-fortanix-unknown-sgx`](platform-support/x86_64-fortanix-unknown-sgx.md) | ✓ | [Fortanix ABI] for 64-bit Intel SGX
 `x86_64-fuchsia` | ✓ | 64-bit Fuchsia
-`x86_64-linux-android` | ✓ | 64-bit x86 Android
+[`x86_64-linux-android`](platform-support/android.md) | ✓ | 64-bit x86 Android
 `x86_64-pc-solaris` | ✓ | 64-bit Solaris 10/11, illumos
 `x86_64-unknown-linux-gnux32` | ✓ | 64-bit Linux (x32 ABI) (kernel 4.15, glibc 2.27)
 [`x86_64-unknown-none`](platform-support/x86_64-unknown-none.md) | * | Freestanding/bare-metal x86_64, softfloat
diff --git a/src/doc/rustc/src/platform-support/android.md b/src/doc/rustc/src/platform-support/android.md
new file mode 100644
index 0000000000000..b2c8e5d4df736
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/android.md
@@ -0,0 +1,45 @@
+# *-linux-android and *-linux-androideabi
+
+**Tier: 2**
+
+[Android] is a mobile operating system built on top of the Linux kernel.
+
+[Android]: https://source.android.com/
+
+## Target maintainers
+
+- Chris Wailes ([@chriswailes](https://github.com/chriswailes))
+- Matthew Maurer ([@maurer](https://github.com/maurer))
+- Martin Geisler ([@mgeisler](https://github.com/mgeisler))
+
+## Requirements
+
+This target is cross-compiled from a host environment. Development may be done
+from the [source tree] or using the Android NDK.
+
+[source tree]: https://source.android.com/docs/setup/build/downloading
+
+Android targets support std. Generated binaries use the ELF file format.
+
+## NDK/API Update Policy
+
+Rust will support the most recent Long Term Support (LTS) Android Native
+Development Kit (NDK).  By default Rust will support all API levels supported
+by the NDK, but a higher minimum API level may be required if deemed necessary.
+
+## Building the target
+
+To build Rust binaries for Android you'll need a copy of the most recent LTS
+edition of the [Android NDK].  Supported Android targets are:
+
+* aarch64-linux-android
+* arm-linux-androideabi
+* armv7-linux-androideabi
+* i686-linux-android
+* thumbv7neon-linux-androideabi
+* x86_64-linux-android
+
+[Android NDK]: https://developer.android.com/ndk/downloads
+
+A list of all supported targets can be found
+[here](https://doc.rust-lang.org/rustc/platform-support.html)
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index e17165440d109..593c1c436b861 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -411,7 +411,7 @@ img {
 
 .sidebar {
 	font-size: 0.875rem;
-	width: 250px;
+	width: 200px;
 	min-width: 200px;
 	overflow-y: scroll;
 	position: sticky;
diff --git a/src/test/rustdoc-gui/code-blocks-overflow.goml b/src/test/rustdoc-gui/code-blocks-overflow.goml
index f93f3f0aefc51..ee4dad444e932 100644
--- a/src/test/rustdoc-gui/code-blocks-overflow.goml
+++ b/src/test/rustdoc-gui/code-blocks-overflow.goml
@@ -5,4 +5,4 @@ size: (1080, 600)
 assert-count: (".docblock > .example-wrap", 2)
 assert: ".docblock > .example-wrap > .language-txt"
 assert: ".docblock > .example-wrap > .rust-example-rendered"
-assert-css: (".docblock > .example-wrap > pre", {"width": "785.25px", "overflow-x": "auto"}, ALL)
+assert-css: (".docblock > .example-wrap > pre", {"width": "796px", "overflow-x": "auto"}, ALL)
diff --git a/src/test/rustdoc-gui/docblock-table-overflow.goml b/src/test/rustdoc-gui/docblock-table-overflow.goml
index 7f97cf220cc55..ef0d37c902e09 100644
--- a/src/test/rustdoc-gui/docblock-table-overflow.goml
+++ b/src/test/rustdoc-gui/docblock-table-overflow.goml
@@ -4,7 +4,7 @@ goto: file://|DOC_PATH|/lib2/long_table/struct.Foo.html
 size: (1100, 800)
 // Logically, the ".docblock" and the "<p>" should have the same scroll width.
 compare-elements-property: (".top-doc .docblock", ".top-doc .docblock > p", ["scrollWidth"])
-assert-property: (".top-doc .docblock", {"scrollWidth": "801"})
+assert-property: (".top-doc .docblock", {"scrollWidth": "816"})
 // However, since there is overflow in the <table>, its scroll width is bigger.
 assert-property: (".top-doc .docblock table", {"scrollWidth": "1572"})
 
@@ -16,6 +16,6 @@ compare-elements-property: (
     "#implementations-list > details .docblock > p",
     ["scrollWidth"],
 )
-assert-property: ("#implementations-list > details .docblock", {"scrollWidth": "801"})
+assert-property: ("#implementations-list > details .docblock", {"scrollWidth": "816"})
 // However, since there is overflow in the <table>, its scroll width is bigger.
 assert-property: ("#implementations-list > details .docblock table", {"scrollWidth": "1572"})
diff --git a/src/test/rustdoc-gui/item-info-overflow.goml b/src/test/rustdoc-gui/item-info-overflow.goml
index 17478da4fea29..bc3addd33dd38 100644
--- a/src/test/rustdoc-gui/item-info-overflow.goml
+++ b/src/test/rustdoc-gui/item-info-overflow.goml
@@ -4,7 +4,7 @@ goto: file://|DOC_PATH|/lib2/struct.LongItemInfo.html
 size: (1200, 870)
 // Logically, the "item-decl" and the "item-info" should have the same scroll width.
 compare-elements-property: (".item-decl", ".item-info", ["scrollWidth"])
-assert-property: (".item-info", {"scrollWidth": "890"})
+assert-property: (".item-info", {"scrollWidth": "940"})
 // Just to be sure we're comparing the correct "item-info":
 assert-text: (
     ".item-info",
@@ -21,7 +21,7 @@ compare-elements-property: (
 )
 assert-property: (
     "#impl-SimpleTrait-for-LongItemInfo2 .item-info",
-    {"scrollWidth": "866"},
+    {"scrollWidth": "916"},
 )
 // Just to be sure we're comparing the correct "item-info":
 assert-text: (
diff --git a/src/test/rustdoc-gui/item-info.goml b/src/test/rustdoc-gui/item-info.goml
index 50c45b76bd630..8750d5c53606f 100644
--- a/src/test/rustdoc-gui/item-info.goml
+++ b/src/test/rustdoc-gui/item-info.goml
@@ -4,9 +4,9 @@ goto: file://|DOC_PATH|/lib2/struct.Foo.html
 // We set a fixed size so there is no chance of "random" resize.
 size: (1100, 800)
 // We check that ".item-info" is bigger than its content.
-assert-css: (".item-info", {"width": "790px"})
+assert-css: (".item-info", {"width": "840px"})
 assert-css: (".item-info .stab", {"width": "289px"})
-assert-position: (".item-info .stab", {"x": 295})
+assert-position: (".item-info .stab", {"x": 245})
 
 // Now we ensure that they're not rendered on the same line.
 goto: file://|DOC_PATH|/lib2/trait.Trait.html
diff --git a/src/test/rustdoc-gui/notable-trait.goml b/src/test/rustdoc-gui/notable-trait.goml
index 7eb00d825a5c3..20a129f9d9da6 100644
--- a/src/test/rustdoc-gui/notable-trait.goml
+++ b/src/test/rustdoc-gui/notable-trait.goml
@@ -18,11 +18,11 @@ compare-elements-position-false: (
 // The `i` should be *after* the type.
 assert-position: (
     "//*[@id='method.create_an_iterator_from_read']//a[text()='NotableStructWithLongName']",
-    {"x": 692},
+    {"x": 677},
 )
 assert-position: (
     "//*[@id='method.create_an_iterator_from_read']//*[@class='notable-traits']",
-    {"x": 966},
+    {"x": 951},
 )
 
 
diff --git a/src/test/rustdoc-gui/search-result-display.goml b/src/test/rustdoc-gui/search-result-display.goml
index efbbfb925bd3b..e33693e27eaf6 100644
--- a/src/test/rustdoc-gui/search-result-display.goml
+++ b/src/test/rustdoc-gui/search-result-display.goml
@@ -7,7 +7,7 @@ press-key: 'Enter'
 wait-for: "#crate-search"
 // The width is returned by "getComputedStyle" which returns the exact number instead of the
 // CSS rule which is "50%"...
-assert-css: (".search-results div.desc", {"width": "293px"})
+assert-css: (".search-results div.desc", {"width": "318px"})
 size: (600, 100)
 // As counter-intuitive as it may seem, in this width, the width is "100%", which is why
 // when computed it's larger.
diff --git a/src/test/rustdoc-gui/sidebar.goml b/src/test/rustdoc-gui/sidebar.goml
index 32fe3334f3644..ea7bcc669945a 100644
--- a/src/test/rustdoc-gui/sidebar.goml
+++ b/src/test/rustdoc-gui/sidebar.goml
@@ -1,5 +1,6 @@
 // Checks multiple things on the sidebar display (width of its elements, colors, etc).
 goto: file://|DOC_PATH|/test_docs/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 show-text: true
 local-storage: {"rustdoc-theme": "light"}
 // We reload the page so the local storage settings are being used.
@@ -39,11 +40,13 @@ assert-property: ("html", {"scrollTop": "0"})
 
 // We now go back to the crate page to click on the "lib2" crate link.
 goto: file://|DOC_PATH|/test_docs/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-css: (".sidebar-elems .crate > ul > li:first-child > a", {"color": "rgb(53, 109, 164)"})
 click: ".sidebar-elems .crate > ul > li:first-child > a"
 
 // PAGE: lib2/index.html
 goto: file://|DOC_PATH|/lib2/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-text: (".sidebar > .location", "Crate lib2")
 // We check that we have the crates list and that the "current" on is now "lib2".
 assert-text: (".sidebar-elems .crate > ul > li > a.current", "lib2")
@@ -65,11 +68,13 @@ assert-text: (".sidebar .sidebar-elems .location", "In lib2")
 assert-false: ".sidebar-elems > .crate"
 
 goto: ./module/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-text: (".sidebar > .location", "Module module")
 // We check that we don't have the crate list.
 assert-false: ".sidebar-elems > .crate"
 
 goto: ./sub_module/sub_sub_module/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-text: (".sidebar > .location", "Module sub_sub_module")
 // We check that we don't have the crate list.
 assert-false: ".sidebar-elems .crate"
@@ -78,11 +83,21 @@ assert-text: ("#functions + .item-table .item-left > a", "foo")
 
 // Links to trait implementations in the sidebar should not wrap even if they are long.
 goto: file://|DOC_PATH|/lib2/struct.HasALongTraitWithParams.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-property: (".sidebar-elems section .block li > a", {"offsetHeight": 29})
 
 // Test that clicking on of the "In <module>" headings in the sidebar links to the
 // appropriate anchor in index.html.
 goto: file://|DOC_PATH|/test_docs/struct.Foo.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 click: ".block.mod h3 a"
 // PAGE: index.html
 assert-css: ("#modules", {"background-color": "rgb(253, 255, 211)"})
+
+// Finally, assert that the `[+]/[−]` toggle doesn't affect sidebar width.
+click: "#toggle-all-docs"
+assert-text: ("#toggle-all-docs", "[+]")
+assert-property: (".sidebar", {"clientWidth": "200"})
+click: "#toggle-all-docs"
+assert-text: ("#toggle-all-docs", "[−]")
+assert-property: (".sidebar", {"clientWidth": "200"})
\ No newline at end of file
diff --git a/src/test/rustdoc-gui/type-declation-overflow.goml b/src/test/rustdoc-gui/type-declation-overflow.goml
index 9a46908f9333b..7b3e9ad5a5717 100644
--- a/src/test/rustdoc-gui/type-declation-overflow.goml
+++ b/src/test/rustdoc-gui/type-declation-overflow.goml
@@ -15,7 +15,7 @@ assert-property: (".item-table .struct", {"offsetWidth": "684"})
 goto: file://|DOC_PATH|/lib2/too_long/type.ReallyLongTypeNameLongLongLong.html
 assert-property: ("body", {"scrollWidth": "1100"})
 // We now check that the section width hasn't grown because of it.
-assert-property: ("#main-content", {"scrollWidth": "825"})
+assert-property: ("#main-content", {"scrollWidth": "840"})
 // And now checking that it has scrollable content.
 assert-property: (".item-decl pre", {"scrollWidth": "1103"})
 
@@ -24,7 +24,7 @@ assert-property: (".item-decl pre", {"scrollWidth": "1103"})
 goto: file://|DOC_PATH|/lib2/too_long/constant.ReallyLongTypeNameLongLongLongConstBecauseWhyNotAConstRightGigaGigaSupraLong.html
 assert-property: ("body", {"scrollWidth": "1100"})
 // We now check that the section width hasn't grown because of it.
-assert-property: ("#main-content", {"scrollWidth": "825"})
+assert-property: ("#main-content", {"scrollWidth": "840"})
 // And now checking that it has scrollable content.
 assert-property: (".item-decl pre", {"scrollWidth": "950"})