Adding upstream version 1.65.0+dfsg1.upstream/1.65.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

120 files changed, 439 insertions, 439 deletions

diff --git a/src/test/ui/issues/auxiliary/issue-2380.rs b/src/test/ui/issues/auxiliary/issue-2380.rs
index 9a51a73c9..79fd62d16 100644
--- a/src/test/ui/issues/auxiliary/issue-2380.rs
+++ b/src/test/ui/issues/auxiliary/issue-2380.rs
@@ -1,8 +1,6 @@
 #![crate_name="a"]
 #![crate_type = "lib"]
 
-#![feature(box_syntax)]
-
 pub trait i<T>
 {
     fn dummy(&self, t: T) -> T { panic!() }
@@ -11,5 +9,5 @@ pub trait i<T>
 pub fn f<T>() -> Box<i<T>+'static> {
     impl<T> i<T> for () { }
 
-    box () as Box<i<T>+'static>
+    Box::new(()) as Box<i<T>+'static>
 }
diff --git a/src/test/ui/issues/issue-100550-normalization-ice-exposed-by-mir-inlining.rs b/src/test/ui/issues/issue-100550-normalization-ice-exposed-by-mir-inlining.rs
deleted file mode 100644
index 2ed50d709..000000000
--- a/src/test/ui/issues/issue-100550-normalization-ice-exposed-by-mir-inlining.rs
+++ /dev/null
@@ -1,39 +0,0 @@
-// check-pass
-
-// compile-flags: --emit=mir,link -O
-
-// There is an ICE somewhere in type normalization, and we are hitting it during
-// the MIR inlining pass on this code.
-//
-// Long term, we should fix that ICE and change the compile-flags for this test
-// to explicitly enable MIR inlining.
-//
-// Short term, we are diabling MIR inlining for Rust 1.64-beta, so that we avoid
-// this ICE in this instance.
-
-pub trait Trait {
-    type Associated;
-}
-impl<T> Trait for T {
-    type Associated = T;
-}
-
-pub struct Struct<T>(<T as Trait>::Associated);
-
-pub fn foo<T>() -> Struct<T>
-where
-    T: Trait,
-{
-    bar()
-}
-
-#[inline]
-fn bar<T>() -> Struct<T> {
-    Struct(baz())
-}
-
-fn baz<T>() -> T {
-    unimplemented!()
-}
-
-fn main() { }
diff --git a/src/test/ui/issues/issue-100605.rs b/src/test/ui/issues/issue-100605.rs
new file mode 100644
index 000000000..917a45c15
--- /dev/null
+++ b/src/test/ui/issues/issue-100605.rs
@@ -0,0 +1,9 @@
+fn takes_option(_arg: Option<&String>) {}
+
+fn main() {
+    takes_option(&None); //~ ERROR 4:18: 4:23: mismatched types [E0308]
+
+    let x = String::from("x");
+    let res = Some(x);
+    takes_option(&res); //~ ERROR 8:18: 8:22: mismatched types [E0308]
+}
diff --git a/src/test/ui/issues/issue-100605.stderr b/src/test/ui/issues/issue-100605.stderr
new file mode 100644
index 000000000..886e3cd6b
--- /dev/null
+++ b/src/test/ui/issues/issue-100605.stderr
@@ -0,0 +1,46 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-100605.rs:4:18
+   |
+LL |     takes_option(&None);
+   |     ------------ ^^^^^ expected enum `Option`, found `&Option<_>`
+   |     |
+   |     arguments to this function are incorrect
+   |
+   = note:   expected enum `Option<&String>`
+           found reference `&Option<_>`
+note: function defined here
+  --> $DIR/issue-100605.rs:1:4
+   |
+LL | fn takes_option(_arg: Option<&String>) {}
+   |    ^^^^^^^^^^^^ ---------------------
+help: you can convert from `&Option<T>` to `Option<&T>` using `.as_ref()`
+   |
+LL |     takes_option(None.as_ref());
+   |                  ~~~~~~~~~~~~~
+help: consider removing the borrow
+   |
+LL -     takes_option(&None);
+LL +     takes_option(None);
+   |
+
+error[E0308]: mismatched types
+  --> $DIR/issue-100605.rs:8:18
+   |
+LL |     takes_option(&res);
+   |     ------------ ^^^^
+   |     |            |
+   |     |            expected enum `Option`, found `&Option<String>`
+   |     |            help: you can convert from `&Option<T>` to `Option<&T>` using `.as_ref()`: `res.as_ref()`
+   |     arguments to this function are incorrect
+   |
+   = note:   expected enum `Option<&String>`
+           found reference `&Option<String>`
+note: function defined here
+  --> $DIR/issue-100605.rs:1:4
+   |
+LL | fn takes_option(_arg: Option<&String>) {}
+   |    ^^^^^^^^^^^^ ---------------------
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/issues/issue-10682.rs b/src/test/ui/issues/issue-10682.rs
index afaa90f05..72e4559d3 100644
--- a/src/test/ui/issues/issue-10682.rs
+++ b/src/test/ui/issues/issue-10682.rs
@@ -4,12 +4,10 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 fn work(_: Box<isize>) {}
 fn foo<F:FnOnce()>(_: F) {}
 
 pub fn main() {
-  let a = box 1;
+  let a = Box::new(1);
   foo(move|| { foo(move|| { work(a) }) })
 }
diff --git a/src/test/ui/issues/issue-10767.rs b/src/test/ui/issues/issue-10767.rs
index f40815fdb..5670cd458 100644
--- a/src/test/ui/issues/issue-10767.rs
+++ b/src/test/ui/issues/issue-10767.rs
@@ -1,10 +1,8 @@
 // run-pass
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 pub fn main() {
     fn f() {
     }
-    let _: Box<fn()> = box (f as fn());
+    let _: Box<fn()> = Box::new(f as fn());
 }
diff --git a/src/test/ui/issues/issue-10802.rs b/src/test/ui/issues/issue-10802.rs
index f1d6b37a6..99e1a92df 100644
--- a/src/test/ui/issues/issue-10802.rs
+++ b/src/test/ui/issues/issue-10802.rs
@@ -1,6 +1,5 @@
 // run-pass
 #![allow(dead_code)]
-#![feature(box_syntax)]
 
 struct DroppableStruct;
 enum DroppableEnum {
@@ -33,14 +32,14 @@ impl  Whatever {
 
 fn main() {
     {
-        let f: Box<_> = box DroppableStruct;
-        let _a = Whatever::new(box f as Box<dyn MyTrait>);
+        let f: Box<_> = Box::new(DroppableStruct);
+        let _a = Whatever::new(Box::new(f) as Box<dyn MyTrait>);
     }
     assert!(unsafe { DROPPED });
     unsafe { DROPPED = false; }
     {
-        let f: Box<_> = box DroppableEnum::DroppableVariant1;
-        let _a = Whatever::new(box f as Box<dyn MyTrait>);
+        let f: Box<_> = Box::new(DroppableEnum::DroppableVariant1);
+        let _a = Whatever::new(Box::new(f) as Box<dyn MyTrait>);
     }
     assert!(unsafe { DROPPED });
 }
diff --git a/src/test/ui/issues/issue-11192.rs b/src/test/ui/issues/issue-11192.rs
index 3bf91675e..1a3d8c9fe 100644
--- a/src/test/ui/issues/issue-11192.rs
+++ b/src/test/ui/issues/issue-11192.rs
@@ -1,20 +1,20 @@
-#![feature(box_syntax)]
-
 struct Foo {
     x: isize
 }
 
+
 impl Drop for Foo {
     fn drop(&mut self) {
         println!("drop {}", self.x);
     }
 }
 
+
 fn main() {
-    let mut ptr: Box<_> = box Foo { x: 0 };
+    let mut ptr: Box<_> = Box::new(Foo { x: 0 });
     let mut test = |foo: &Foo| {
         println!("access {}", foo.x);
-        ptr = box Foo { x: ptr.x + 1 };
+        ptr = Box::new(Foo { x: ptr.x + 1 });
         println!("access {}", foo.x);
     };
     test(&*ptr);
diff --git a/src/test/ui/issues/issue-11192.stderr b/src/test/ui/issues/issue-11192.stderr
index 2a9d91317..fc1548013 100644
--- a/src/test/ui/issues/issue-11192.stderr
+++ b/src/test/ui/issues/issue-11192.stderr
@@ -4,7 +4,7 @@ error[E0502]: cannot borrow `*ptr` as immutable because it is also borrowed as m
 LL |     let mut test = |foo: &Foo| {
    |                    ----------- mutable borrow occurs here
 LL |         println!("access {}", foo.x);
-LL |         ptr = box Foo { x: ptr.x + 1 };
+LL |         ptr = Box::new(Foo { x: ptr.x + 1 });
    |         --- first borrow occurs due to use of `ptr` in closure
 ...
 LL |     test(&*ptr);
diff --git a/src/test/ui/issues/issue-11374.stderr b/src/test/ui/issues/issue-11374.stderr
index 3a1d43310..15b2bbeb7 100644
--- a/src/test/ui/issues/issue-11374.stderr
+++ b/src/test/ui/issues/issue-11374.stderr
@@ -14,7 +14,7 @@ note: associated function defined here
   --> $DIR/issue-11374.rs:13:12
    |
 LL |     pub fn read_to(&mut self, vec: &mut [u8]) {
-   |            ^^^^^^^ ---------  --------------
+   |            ^^^^^^^            --------------
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-11515.rs b/src/test/ui/issues/issue-11515.rs
index 2072f9c47..b5c942f96 100644
--- a/src/test/ui/issues/issue-11515.rs
+++ b/src/test/ui/issues/issue-11515.rs
@@ -1,10 +1,10 @@
-#![feature(box_syntax)]
-
 struct Test {
     func: Box<dyn FnMut() + 'static>,
 }
 
+
+
 fn main() {
     let closure: Box<dyn Fn() + 'static> = Box::new(|| ());
-    let test = box Test { func: closure }; //~ ERROR trait upcasting coercion is experimental [E0658]
+    let test = Box::new(Test { func: closure }); //~ ERROR trait upcasting coercion is experimental [E0658]
 }
diff --git a/src/test/ui/issues/issue-11515.stderr b/src/test/ui/issues/issue-11515.stderr
index 17bfae2a4..accd47f0f 100644
--- a/src/test/ui/issues/issue-11515.stderr
+++ b/src/test/ui/issues/issue-11515.stderr
@@ -1,8 +1,8 @@
 error[E0658]: cannot cast `dyn Fn()` to `dyn FnMut()`, trait upcasting coercion is experimental
-  --> $DIR/issue-11515.rs:9:33
+  --> $DIR/issue-11515.rs:9:38
    |
-LL |     let test = box Test { func: closure };
-   |                                 ^^^^^^^
+LL |     let test = Box::new(Test { func: closure });
+   |                                      ^^^^^^^
    |
    = note: see issue #65991 <https://github.com/rust-lang/rust/issues/65991> for more information
    = help: add `#![feature(trait_upcasting)]` to the crate attributes to enable
diff --git a/src/test/ui/issues/issue-11552.rs b/src/test/ui/issues/issue-11552.rs
index bae12375d..9fb9f3d2e 100644
--- a/src/test/ui/issues/issue-11552.rs
+++ b/src/test/ui/issues/issue-11552.rs
@@ -1,6 +1,5 @@
 // run-pass
 #![feature(box_patterns)]
-#![feature(box_syntax)]
 
 #[derive(Clone)]
 enum Noun
@@ -18,5 +17,8 @@ fn fas(n: &Noun) -> Noun
 }
 
 pub fn main() {
-    fas(&Noun::Cell(box Noun::Atom(2), box Noun::Cell(box Noun::Atom(2), box Noun::Atom(3))));
+    fas(
+        &Noun::Cell(Box::new(Noun::Atom(2)),
+        Box::new(Noun::Cell(Box::new(Noun::Atom(2)), Box::new(Noun::Atom(3)))))
+    );
 }
diff --git a/src/test/ui/issues/issue-11844.rs b/src/test/ui/issues/issue-11844.rs
index bb06f00d5..f974a4702 100644
--- a/src/test/ui/issues/issue-11844.rs
+++ b/src/test/ui/issues/issue-11844.rs
@@ -1,7 +1,5 @@
-#![feature(box_syntax)]
-
 fn main() {
-    let a = Some(box 1);
+    let a = Some(Box::new(1));
     match a {
         Ok(a) => //~ ERROR: mismatched types
             println!("{}",a),
diff --git a/src/test/ui/issues/issue-11844.stderr b/src/test/ui/issues/issue-11844.stderr
index 9d7470e7a..81cf918a1 100644
--- a/src/test/ui/issues/issue-11844.stderr
+++ b/src/test/ui/issues/issue-11844.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-11844.rs:6:9
+  --> $DIR/issue-11844.rs:4:9
    |
 LL |     match a {
    |           - this expression has type `Option<Box<{integer}>>`
diff --git a/src/test/ui/issues/issue-12127.rs b/src/test/ui/issues/issue-12127.rs
index bb2c27345..8b30ddc2d 100644
--- a/src/test/ui/issues/issue-12127.rs
+++ b/src/test/ui/issues/issue-12127.rs
@@ -1,10 +1,10 @@
-#![feature(box_syntax, unboxed_closures)]
+#![feature(unboxed_closures)]
 
 fn to_fn_once<A,F:FnOnce<A>>(f: F) -> F { f }
 fn do_it(x: &isize) { }
 
 fn main() {
-    let x: Box<_> = box 22;
+    let x: Box<_> = Box::new(22);
     let f = to_fn_once(move|| do_it(&*x));
     to_fn_once(move|| {
         f();
diff --git a/src/test/ui/issues/issue-13323.rs b/src/test/ui/issues/issue-13323.rs
index 26847ee7a..71e14d4da 100644
--- a/src/test/ui/issues/issue-13323.rs
+++ b/src/test/ui/issues/issue-13323.rs
@@ -1,5 +1,4 @@
 // run-pass
-#![feature(box_syntax)]
 
 struct StrWrap {
     s: String
@@ -48,7 +47,7 @@ impl<T: Eq> Matcher<T> for EqualTo<T> {
 }
 
 fn equal_to<T: Eq>(expected: T) -> Box<EqualTo<T>> {
-    box EqualTo { expected: expected }
+    Box::new(EqualTo { expected: expected })
 }
 
 pub fn main() {
diff --git a/src/test/ui/issues/issue-14399.rs b/src/test/ui/issues/issue-14399.rs
index 6bf8a5899..7b32bf8e4 100644
--- a/src/test/ui/issues/issue-14399.rs
+++ b/src/test/ui/issues/issue-14399.rs
@@ -6,8 +6,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 #[derive(Clone)]
 struct B1;
 
@@ -15,6 +13,6 @@ trait A { fn foo(&self) {} }
 impl A for B1 {}
 
 fn main() {
-    let v: Box<_> = box B1;
+    let v: Box<_> = Box::new(B1);
     let _c: Box<dyn A> = v.clone();
 }
diff --git a/src/test/ui/issues/issue-14915.rs b/src/test/ui/issues/issue-14915.rs
index 909540355..127b909dd 100644
--- a/src/test/ui/issues/issue-14915.rs
+++ b/src/test/ui/issues/issue-14915.rs
@@ -1,7 +1,5 @@
-#![feature(box_syntax)]
-
 fn main() {
-    let x: Box<isize> = box 0;
+    let x: Box<isize> = Box::new(0);
 
     println!("{}", x + 1);
     //~^ ERROR cannot add `{integer}` to `Box<isize>`
diff --git a/src/test/ui/issues/issue-14915.stderr b/src/test/ui/issues/issue-14915.stderr
index bd0b1d39a..6e6326929 100644
--- a/src/test/ui/issues/issue-14915.stderr
+++ b/src/test/ui/issues/issue-14915.stderr
@@ -1,5 +1,5 @@
 error[E0369]: cannot add `{integer}` to `Box<isize>`
-  --> $DIR/issue-14915.rs:6:22
+  --> $DIR/issue-14915.rs:4:22
    |
 LL |     println!("{}", x + 1);
    |                    - ^ - {integer}
diff --git a/src/test/ui/issues/issue-15524.rs b/src/test/ui/issues/issue-15524.rs
deleted file mode 100644
index 565db2d0f..000000000
--- a/src/test/ui/issues/issue-15524.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-const N: isize = 1;
-
-enum Foo {
-    //~^ ERROR discriminant value `1` assigned more than once
-    //~| ERROR discriminant value `1` assigned more than once
-    //~| ERROR discriminant value `1` assigned more than once
-    A = 1,
-    B = 1,
-    C = 0,
-    D,
-
-    E = N,
-
-}
-
-fn main() {}
diff --git a/src/test/ui/issues/issue-15524.stderr b/src/test/ui/issues/issue-15524.stderr
deleted file mode 100644
index 1195e0a34..000000000
--- a/src/test/ui/issues/issue-15524.stderr
+++ /dev/null
@@ -1,40 +0,0 @@
-error[E0081]: discriminant value `1` assigned more than once
-  --> $DIR/issue-15524.rs:3:1
-   |
-LL | enum Foo {
-   | ^^^^^^^^
-...
-LL |     A = 1,
-   |         - first assignment of `1`
-LL |     B = 1,
-   |         - second assignment of `1`
-
-error[E0081]: discriminant value `1` assigned more than once
-  --> $DIR/issue-15524.rs:3:1
-   |
-LL | enum Foo {
-   | ^^^^^^^^
-...
-LL |     A = 1,
-   |         - first assignment of `1`
-LL |     B = 1,
-LL |     C = 0,
-   |     ----- assigned discriminant for `D` was incremented from this discriminant
-LL |     D,
-   |     - second assignment of `1`
-
-error[E0081]: discriminant value `1` assigned more than once
-  --> $DIR/issue-15524.rs:3:1
-   |
-LL | enum Foo {
-   | ^^^^^^^^
-...
-LL |     A = 1,
-   |         - first assignment of `1`
-...
-LL |     E = N,
-   |         - second assignment of `1`
-
-error: aborting due to 3 previous errors
-
-For more information about this error, try `rustc --explain E0081`.
diff --git a/src/test/ui/issues/issue-15571.rs b/src/test/ui/issues/issue-15571.rs
index 5381d6523..5f228b286 100644
--- a/src/test/ui/issues/issue-15571.rs
+++ b/src/test/ui/issues/issue-15571.rs
@@ -1,8 +1,7 @@
 // run-pass
-#![feature(box_syntax)]
 
 fn match_on_local() {
-    let mut foo: Option<Box<_>> = Some(box 5);
+    let mut foo: Option<Box<_>> = Some(Box::new(5));
     match foo {
         None => {},
         Some(x) => {
@@ -37,7 +36,7 @@ fn match_on_binding() {
 }
 
 fn match_on_upvar() {
-    let mut foo: Option<Box<_>> = Some(box 8);
+    let mut foo: Option<Box<_>> = Some(Box::new(8));
     let f = move|| {
         match foo {
             None => {},
@@ -52,7 +51,7 @@ fn match_on_upvar() {
 
 fn main() {
     match_on_local();
-    match_on_arg(Some(box 6));
+    match_on_arg(Some(Box::new(6)));
     match_on_binding();
     match_on_upvar();
 }
diff --git a/src/test/ui/issues/issue-15763.rs b/src/test/ui/issues/issue-15763.rs
index 9ceffff2e..ae0863615 100644
--- a/src/test/ui/issues/issue-15763.rs
+++ b/src/test/ui/issues/issue-15763.rs
@@ -1,6 +1,5 @@
 // run-pass
 #![allow(unreachable_code)]
-#![feature(box_syntax)]
 
 #[derive(PartialEq, Debug)]
 struct Bar {
@@ -78,12 +77,12 @@ fn main() {
     assert_eq!(cc().unwrap(), 3);
     assert_eq!(dd().unwrap(), 3);
 
-    let i = box 32isize as Box<dyn A>;
+    let i = Box::new(32isize) as Box<dyn A>;
     assert_eq!(i.aaa(), 3);
-    let i = box 32isize as Box<dyn A>;
+    let i = Box::new(32isize) as Box<dyn A>;
     assert_eq!(i.bbb(), 3);
-    let i = box 32isize as Box<dyn A>;
+    let i = Box::new(32isize) as Box<dyn A>;
     assert_eq!(i.ccc().unwrap(), 3);
-    let i = box 32isize as Box<dyn A>;
+    let i = Box::new(32isize) as Box<dyn A>;
     assert_eq!(i.ddd().unwrap(), 3);
 }
diff --git a/src/test/ui/issues/issue-16538.mir.stderr b/src/test/ui/issues/issue-16538.mir.stderr
index 7dab7de76..e320df4b7 100644
--- a/src/test/ui/issues/issue-16538.mir.stderr
+++ b/src/test/ui/issues/issue-16538.mir.stderr
@@ -5,6 +5,7 @@ LL | static foo: &Y::X = &*Y::foo(Y::x as *const Y::X);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
 
 error[E0133]: use of extern static is unsafe and requires unsafe function or block
   --> $DIR/issue-16538.rs:14:30
diff --git a/src/test/ui/issues/issue-16538.thir.stderr b/src/test/ui/issues/issue-16538.thir.stderr
index a18b0197d..4a8628692 100644
--- a/src/test/ui/issues/issue-16538.thir.stderr
+++ b/src/test/ui/issues/issue-16538.thir.stderr
@@ -21,6 +21,7 @@ LL | static foo: &Y::X = &*Y::foo(Y::x as *const Y::X);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/issues/issue-16739.rs b/src/test/ui/issues/issue-16739.rs
index 94da2ca5c..b21ea4bcd 100644
--- a/src/test/ui/issues/issue-16739.rs
+++ b/src/test/ui/issues/issue-16739.rs
@@ -1,5 +1,4 @@
 // run-pass
-#![feature(box_syntax)]
 #![feature(unboxed_closures, fn_traits)]
 
 // Test that unboxing shim for calling rust-call ABI methods through a
@@ -35,12 +34,12 @@ impl FnOnce<(u32,u32)> for Foo {
 }
 
 fn main() {
-    let mut f = box Foo { foo: 42 } as Box<dyn FnMut() -> u32>;
+    let mut f = Box::new(Foo { foo: 42 }) as Box<dyn FnMut() -> u32>;
     assert_eq!(f.call_mut(()), 42);
 
-    let mut f = box Foo { foo: 40 } as Box<dyn FnMut(u32) -> u32>;
+    let mut f = Box::new(Foo { foo: 40 }) as Box<dyn FnMut(u32) -> u32>;
     assert_eq!(f.call_mut((2,)), 42);
 
-    let mut f = box Foo { foo: 40 } as Box<dyn FnMut(u32, u32) -> u32>;
+    let mut f = Box::new(Foo { foo: 40 }) as Box<dyn FnMut(u32, u32) -> u32>;
     assert_eq!(f.call_mut((1, 1)), 42);
 }
diff --git a/src/test/ui/issues/issue-16774.rs b/src/test/ui/issues/issue-16774.rs
index 9e9b84034..2b308ef76 100644
--- a/src/test/ui/issues/issue-16774.rs
+++ b/src/test/ui/issues/issue-16774.rs
@@ -1,5 +1,4 @@
 // run-pass
-#![feature(box_syntax)]
 #![feature(box_patterns)]
 
 use std::ops::{Deref, DerefMut};
@@ -35,7 +34,7 @@ impl DerefMut for X {
 
 fn main() {
     {
-        let mut test = X(box 5);
+        let mut test = X(Box::new(5));
         {
             let mut change = || { *test = 10 };
             change();
diff --git a/src/test/ui/issues/issue-16939.stderr b/src/test/ui/issues/issue-16939.stderr
index aaa3c49b3..766456454 100644
--- a/src/test/ui/issues/issue-16939.stderr
+++ b/src/test/ui/issues/issue-16939.stderr
@@ -12,7 +12,7 @@ LL | fn _foo<F: Fn()> (f: F) {
 help: remove the extra argument
    |
 LL |     |t| f();
-   |         ~~~
+   |          ~~
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-17252.stderr b/src/test/ui/issues/issue-17252.stderr
index 3a629e1eb..4856418ed 100644
--- a/src/test/ui/issues/issue-17252.stderr
+++ b/src/test/ui/issues/issue-17252.stderr
@@ -2,7 +2,7 @@ error[E0391]: cycle detected when const-evaluating + checking `FOO`
   --> $DIR/issue-17252.rs:1:1
    |
 LL | const FOO: usize = FOO;
-   | ^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: ...which immediately requires const-evaluating + checking `FOO` again
 note: cycle used when const-evaluating + checking `main::{constant#0}`
diff --git a/src/test/ui/issues/issue-17322.rs b/src/test/ui/issues/issue-17322.rs
index 20a8d1361..b4fc40c3f 100644
--- a/src/test/ui/issues/issue-17322.rs
+++ b/src/test/ui/issues/issue-17322.rs
@@ -1,8 +1,6 @@
 // run-pass
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 use std::io::{self, Write};
 
 fn f(wr: &mut dyn Write) {
@@ -10,6 +8,6 @@ fn f(wr: &mut dyn Write) {
 }
 
 fn main() {
-    let mut wr = box io::stdout() as Box<dyn Write>;
+    let mut wr = Box::new(io::stdout()) as Box<dyn Write>;
     f(&mut wr);
 }
diff --git a/src/test/ui/issues/issue-18611.stderr b/src/test/ui/issues/issue-18611.stderr
index bd18d4622..22c3470b6 100644
--- a/src/test/ui/issues/issue-18611.stderr
+++ b/src/test/ui/issues/issue-18611.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `isize: HasState` is not satisfied
-  --> $DIR/issue-18611.rs:1:18
+  --> $DIR/issue-18611.rs:1:1
    |
-LL | fn add_state(op: <isize as HasState>::State) {
-   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HasState` is not implemented for `isize`
+LL | / fn add_state(op: <isize as HasState>::State) {
+LL | |
+LL | | }
+   | |_^ the trait `HasState` is not implemented for `isize`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-18819.stderr b/src/test/ui/issues/issue-18819.stderr
index 6499dd0d8..767fdd5ca 100644
--- a/src/test/ui/issues/issue-18819.stderr
+++ b/src/test/ui/issues/issue-18819.stderr
@@ -2,11 +2,13 @@ error[E0061]: this function takes 2 arguments but 1 argument was supplied
   --> $DIR/issue-18819.rs:16:5
    |
 LL |     print_x(X);
-   |     ^^^^^^^---
-   |            ||
-   |            |expected reference, found struct `X`
-   |            an argument of type `&str` is missing
+   |     ^^^^^^^--- an argument of type `&str` is missing
    |
+note: expected reference, found struct `X`
+  --> $DIR/issue-18819.rs:16:13
+   |
+LL |     print_x(X);
+   |             ^
    = note: expected reference `&dyn Foo<Item = bool>`
                  found struct `X`
 note: function defined here
@@ -21,7 +23,7 @@ LL |     print_x(&X);
 help: provide the argument
    |
 LL |     print_x(/* &dyn Foo<Item = bool> */, /* &str */);
-   |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-20162.stderr b/src/test/ui/issues/issue-20162.stderr
index d70bf6e1d..3f9b3be98 100644
--- a/src/test/ui/issues/issue-20162.stderr
+++ b/src/test/ui/issues/issue-20162.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `X: Ord` is not satisfied
-  --> $DIR/issue-20162.rs:5:7
+  --> $DIR/issue-20162.rs:5:5
    |
 LL |     b.sort();
-   |       ^^^^ the trait `Ord` is not implemented for `X`
+   |     ^ ---- required by a bound introduced by this call
+   |     |
+   |     the trait `Ord` is not implemented for `X`
    |
 note: required by a bound in `slice::<impl [T]>::sort`
   --> $SRC_DIR/alloc/src/slice.rs:LL:COL
diff --git a/src/test/ui/issues/issue-20413.stderr b/src/test/ui/issues/issue-20413.stderr
index ea493c58a..2db60b641 100644
--- a/src/test/ui/issues/issue-20413.stderr
+++ b/src/test/ui/issues/issue-20413.stderr
@@ -14,13 +14,13 @@ LL | impl<T> Foo for T where NoData<T>: Foo {
    |                                    ^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_20413`)
-note: required because of the requirements on the impl of `Foo` for `NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+note: required for `NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<NoData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>` to implement `Foo`
   --> $DIR/issue-20413.rs:8:9
    |
 LL | impl<T> Foo for T where NoData<T>: Foo {
    |         ^^^     ^
    = note: 127 redundant requirements hidden
-   = note: required because of the requirements on the impl of `Foo` for `NoData<T>`
+   = note: required for `NoData<T>` to implement `Foo`
 
 error[E0275]: overflow evaluating the requirement `EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>: Baz`
   --> $DIR/issue-20413.rs:27:42
@@ -29,18 +29,18 @@ LL | impl<T> Bar for T where EvenLessData<T>: Baz {
    |                                          ^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_20413`)
-note: required because of the requirements on the impl of `Bar` for `AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+note: required for `AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>` to implement `Bar`
   --> $DIR/issue-20413.rs:27:9
    |
 LL | impl<T> Bar for T where EvenLessData<T>: Baz {
    |         ^^^     ^
-note: required because of the requirements on the impl of `Baz` for `EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+note: required for `EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>` to implement `Baz`
   --> $DIR/issue-20413.rs:34:9
    |
 LL | impl<T> Baz for T where AlmostNoData<T>: Bar {
    |         ^^^     ^
    = note: 126 redundant requirements hidden
-   = note: required because of the requirements on the impl of `Baz` for `EvenLessData<T>`
+   = note: required for `EvenLessData<T>` to implement `Baz`
 
 error[E0275]: overflow evaluating the requirement `AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>: Bar`
   --> $DIR/issue-20413.rs:34:42
@@ -49,18 +49,18 @@ LL | impl<T> Baz for T where AlmostNoData<T>: Bar {
    |                                          ^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_20413`)
-note: required because of the requirements on the impl of `Baz` for `EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+note: required for `EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>` to implement `Baz`
   --> $DIR/issue-20413.rs:34:9
    |
 LL | impl<T> Baz for T where AlmostNoData<T>: Bar {
    |         ^^^     ^
-note: required because of the requirements on the impl of `Bar` for `AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+note: required for `AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<EvenLessData<AlmostNoData<T>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>` to implement `Bar`
   --> $DIR/issue-20413.rs:27:9
    |
 LL | impl<T> Bar for T where EvenLessData<T>: Baz {
    |         ^^^     ^
    = note: 126 redundant requirements hidden
-   = note: required because of the requirements on the impl of `Bar` for `AlmostNoData<T>`
+   = note: required for `AlmostNoData<T>` to implement `Bar`
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/issues/issue-20605.stderr b/src/test/ui/issues/issue-20605.stderr
index 41eefe3f8..e1858b639 100644
--- a/src/test/ui/issues/issue-20605.stderr
+++ b/src/test/ui/issues/issue-20605.stderr
@@ -2,10 +2,10 @@ error[E0277]: the size for values of type `dyn Iterator<Item = &'a mut u8>` cann
   --> $DIR/issue-20605.rs:2:17
    |
 LL |     for item in *things { *item = 0 }
-   |                 ^^^^^^^ expected an implementor of trait `IntoIterator`
+   |                 ^^^^^^^ the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
    |
    = note: the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
-   = note: required because of the requirements on the impl of `IntoIterator` for `dyn Iterator<Item = &'a mut u8>`
+   = note: required for `dyn Iterator<Item = &'a mut u8>` to implement `IntoIterator`
 help: consider mutably borrowing here
    |
 LL |     for item in &mut *things { *item = 0 }
diff --git a/src/test/ui/issues/issue-20831-debruijn.stderr b/src/test/ui/issues/issue-20831-debruijn.stderr
index 57f9575bd..ef62dece8 100644
--- a/src/test/ui/issues/issue-20831-debruijn.stderr
+++ b/src/test/ui/issues/issue-20831-debruijn.stderr
@@ -1,8 +1,14 @@
 error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
-  --> $DIR/issue-20831-debruijn.rs:28:8
+  --> $DIR/issue-20831-debruijn.rs:28:5
    |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |        ^^^^^^^^^
+LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
+LL | |         // Not obvious, but there is an implicit lifetime here -------^
+LL | |
+LL | |         //
+...  |
+LL | |         self.sub = t;
+LL | |     }
+   | |_____^
    |
 note: first, the lifetime cannot outlive the anonymous lifetime defined here...
   --> $DIR/issue-20831-debruijn.rs:28:58
@@ -15,10 +21,16 @@ note: ...but the lifetime must also be valid for the lifetime `'a` as defined he
 LL | impl<'a> Publisher<'a> for MyStruct<'a> {
    |      ^^
 note: ...so that the types are compatible
-  --> $DIR/issue-20831-debruijn.rs:28:8
+  --> $DIR/issue-20831-debruijn.rs:28:5
    |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |        ^^^^^^^^^
+LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
+LL | |         // Not obvious, but there is an implicit lifetime here -------^
+LL | |
+LL | |         //
+...  |
+LL | |         self.sub = t;
+LL | |     }
+   | |_____^
    = note: expected `<MyStruct<'a> as Publisher<'_>>`
               found `<MyStruct<'_> as Publisher<'_>>`
 
diff --git a/src/test/ui/issues/issue-21033.rs b/src/test/ui/issues/issue-21033.rs
index 86cc7707e..91f72eb36 100644
--- a/src/test/ui/issues/issue-21033.rs
+++ b/src/test/ui/issues/issue-21033.rs
@@ -4,7 +4,6 @@
 // pretty-expanded FIXME #23616
 
 #![feature(box_patterns)]
-#![feature(box_syntax)]
 
 enum E {
     StructVar { boxed: Box<i32> }
@@ -13,7 +12,7 @@ enum E {
 fn main() {
 
     // Test matching each shorthand notation for field patterns.
-    let mut a = E::StructVar { boxed: box 3 };
+    let mut a = E::StructVar { boxed: Box::new(3) };
     match a {
         E::StructVar { box boxed } => { }
     }
@@ -38,7 +37,7 @@ fn main() {
 
     // Test matching non shorthand notation. Recreate a since last test
     // moved `boxed`
-    let mut a = E::StructVar { boxed: box 3 };
+    let mut a = E::StructVar { boxed: Box::new(3) };
     match a {
         E::StructVar { boxed: box ref mut num } => { }
     }
diff --git a/src/test/ui/issues/issue-21763.stderr b/src/test/ui/issues/issue-21763.stderr
index b8b38c0a7..72c650297 100644
--- a/src/test/ui/issues/issue-21763.stderr
+++ b/src/test/ui/issues/issue-21763.stderr
@@ -1,12 +1,12 @@
 error[E0277]: `Rc<()>` cannot be sent between threads safely
-  --> $DIR/issue-21763.rs:9:5
+  --> $DIR/issue-21763.rs:9:11
    |
 LL |     foo::<HashMap<Rc<()>, Rc<()>>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Rc<()>` cannot be sent between threads safely
+   |           ^^^^^^^^^^^^^^^^^^^^^^^ `Rc<()>` cannot be sent between threads safely
    |
    = help: within `(Rc<()>, Rc<()>)`, the trait `Send` is not implemented for `Rc<()>`
    = note: required because it appears within the type `(Rc<()>, Rc<()>)`
-   = note: required because of the requirements on the impl of `Send` for `hashbrown::raw::RawTable<(Rc<()>, Rc<()>)>`
+   = note: required for `hashbrown::raw::RawTable<(Rc<()>, Rc<()>)>` to implement `Send`
    = note: required because it appears within the type `hashbrown::map::HashMap<Rc<()>, Rc<()>, RandomState>`
    = note: required because it appears within the type `HashMap<Rc<()>, Rc<()>>`
 note: required by a bound in `foo`
diff --git a/src/test/ui/issues/issue-21950.stderr b/src/test/ui/issues/issue-21950.stderr
index 4909398bb..731615a6b 100644
--- a/src/test/ui/issues/issue-21950.stderr
+++ b/src/test/ui/issues/issue-21950.stderr
@@ -1,3 +1,12 @@
+error[E0191]: the value of the associated type `Output` (from trait `Add`) must be specified
+  --> $DIR/issue-21950.rs:10:25
+   |
+LL |     type Output;
+   |     ----------- `Output` defined here
+...
+LL |     let x = &10 as &dyn Add;
+   |                         ^^^ help: specify the associated type: `Add<Output = Type>`
+
 error[E0393]: the type parameter `Rhs` must be explicitly specified
   --> $DIR/issue-21950.rs:10:25
    |
@@ -9,15 +18,6 @@ LL |     let x = &10 as &dyn Add;
    |
    = note: because of the default `Self` reference, type parameters must be specified on object types
 
-error[E0191]: the value of the associated type `Output` (from trait `Add`) must be specified
-  --> $DIR/issue-21950.rs:10:25
-   |
-LL |     type Output;
-   |     ----------- `Output` defined here
-...
-LL |     let x = &10 as &dyn Add;
-   |                         ^^^ help: specify the associated type: `Add<Output = Type>`
-
 error: aborting due to 2 previous errors
 
 Some errors have detailed explanations: E0191, E0393.
diff --git a/src/test/ui/issues/issue-22872.stderr b/src/test/ui/issues/issue-22872.stderr
index a84cb7d8c..7382d40c0 100644
--- a/src/test/ui/issues/issue-22872.stderr
+++ b/src/test/ui/issues/issue-22872.stderr
@@ -5,7 +5,7 @@ LL |     let _: Box<dyn for<'b> Wrap<'b>> = Box::new(Wrapper(process));
    |                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^ `<P as Process<'_>>::Item` is not an iterator
    |
    = help: the trait `Iterator` is not implemented for `<P as Process<'_>>::Item`
-note: required because of the requirements on the impl of `for<'b> Wrap<'b>` for `Wrapper<P>`
+note: required for `Wrapper<P>` to implement `for<'b> Wrap<'b>`
   --> $DIR/issue-22872.rs:7:13
    |
 LL | impl<'b, P> Wrap<'b> for Wrapper<P>
diff --git a/src/test/ui/issues/issue-2288.rs b/src/test/ui/issues/issue-2288.rs
index c74e53fca..6fd690a4d 100644
--- a/src/test/ui/issues/issue-2288.rs
+++ b/src/test/ui/issues/issue-2288.rs
@@ -1,8 +1,6 @@
 // run-pass
 #![allow(non_camel_case_types)]
 
-#![feature(box_syntax)]
-
 trait clam<A> {
   fn chowder(&self, y: A);
 }
@@ -30,6 +28,6 @@ fn f<A>(x: Box<dyn clam<A>>, a: A) {
 pub fn main() {
 
   let c = foo(42);
-  let d: Box<dyn clam<isize>> = box c as Box<dyn clam<isize>>;
+  let d: Box<dyn clam<isize>> = Box::new(c) as Box<dyn clam<isize>>;
   f(d, c.x);
 }
diff --git a/src/test/ui/issues/issue-23024.rs b/src/test/ui/issues/issue-23024.rs
index e92273bd4..010281ee3 100644
--- a/src/test/ui/issues/issue-23024.rs
+++ b/src/test/ui/issues/issue-23024.rs
@@ -1,11 +1,10 @@
-#![feature(box_syntax)]
 use std::any::Any;
 
 fn main()
 {
     fn h(x:i32) -> i32 {3*x}
     let mut vfnfer:Vec<Box<dyn Any>> = vec![];
-    vfnfer.push(box h);
+    vfnfer.push(Box::new(h));
     println!("{:?}",(vfnfer[0] as dyn Fn)(3));
     //~^ ERROR the precise format of `Fn`-family traits'
     //~| ERROR missing generics for trait `Fn`
diff --git a/src/test/ui/issues/issue-23024.stderr b/src/test/ui/issues/issue-23024.stderr
index 7a4d90b44..73f93c51d 100644
--- a/src/test/ui/issues/issue-23024.stderr
+++ b/src/test/ui/issues/issue-23024.stderr
@@ -1,5 +1,5 @@
 error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change
-  --> $DIR/issue-23024.rs:9:39
+  --> $DIR/issue-23024.rs:8:39
    |
 LL |     println!("{:?}",(vfnfer[0] as dyn Fn)(3));
    |                                       ^^ help: use parenthetical notation instead: `Fn() -> ()`
@@ -8,7 +8,7 @@ LL |     println!("{:?}",(vfnfer[0] as dyn Fn)(3));
    = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
 
 error[E0107]: missing generics for trait `Fn`
-  --> $DIR/issue-23024.rs:9:39
+  --> $DIR/issue-23024.rs:8:39
    |
 LL |     println!("{:?}",(vfnfer[0] as dyn Fn)(3));
    |                                       ^^ expected 1 generic argument
@@ -24,7 +24,7 @@ LL |     println!("{:?}",(vfnfer[0] as dyn Fn<Args>)(3));
    |                                       ~~~~~~~~
 
 error[E0191]: the value of the associated type `Output` (from trait `FnOnce`) must be specified
-  --> $DIR/issue-23024.rs:9:39
+  --> $DIR/issue-23024.rs:8:39
    |
 LL |     println!("{:?}",(vfnfer[0] as dyn Fn)(3));
    |                                       ^^ help: specify the associated type: `Fn<Output = Type>`
diff --git a/src/test/ui/issues/issue-23122-2.stderr b/src/test/ui/issues/issue-23122-2.stderr
index 7519e632d..f6cda3de5 100644
--- a/src/test/ui/issues/issue-23122-2.stderr
+++ b/src/test/ui/issues/issue-23122-2.stderr
@@ -1,15 +1,10 @@
-error[E0275]: overflow evaluating the requirement `<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next: Sized`
+error[E0275]: overflow evaluating the requirement `<T as Next>::Next`
   --> $DIR/issue-23122-2.rs:10:17
    |
 LL |     type Next = <GetNext<T::Next> as Next>::Next;
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_23122_2`)
-note: required because of the requirements on the impl of `Next` for `GetNext<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next>`
-  --> $DIR/issue-23122-2.rs:9:15
-   |
-LL | impl<T: Next> Next for GetNext<T> {
-   |               ^^^^     ^^^^^^^^^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-23302-3.stderr b/src/test/ui/issues/issue-23302-3.stderr
index dcb99605d..074939f68 100644
--- a/src/test/ui/issues/issue-23302-3.stderr
+++ b/src/test/ui/issues/issue-23302-3.stderr
@@ -2,13 +2,13 @@ error[E0391]: cycle detected when const-evaluating + checking `A`
   --> $DIR/issue-23302-3.rs:1:1
    |
 LL | const A: i32 = B;
-   | ^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^
    |
 note: ...which requires const-evaluating + checking `B`...
   --> $DIR/issue-23302-3.rs:3:1
    |
 LL | const B: i32 = A;
-   | ^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^
    = note: ...which again requires const-evaluating + checking `A`, completing the cycle
 note: cycle used when simplifying constant for the type system `A`
   --> $DIR/issue-23302-3.rs:1:1
diff --git a/src/test/ui/issues/issue-23491.rs b/src/test/ui/issues/issue-23491.rs
index 1cb969731..e5f9dd3ef 100644
--- a/src/test/ui/issues/issue-23491.rs
+++ b/src/test/ui/issues/issue-23491.rs
@@ -1,9 +1,8 @@
 // run-pass
 #![allow(unused_variables)]
-#![feature(box_syntax)]
 
 struct Node<T: ?Sized>(#[allow(unused_tuple_struct_fields)] T);
 
 fn main() {
-    let x: Box<Node<[isize]>> = box Node([]);
+    let x: Box<Node<[isize]>> = Box::new(Node([]));
 }
diff --git a/src/test/ui/issues/issue-23611-enum-swap-in-drop.rs b/src/test/ui/issues/issue-23611-enum-swap-in-drop.rs
index 403cf970b..cdb130d60 100644
--- a/src/test/ui/issues/issue-23611-enum-swap-in-drop.rs
+++ b/src/test/ui/issues/issue-23611-enum-swap-in-drop.rs
@@ -97,7 +97,7 @@ pub fn main() {
     // ever hands f_A off to instances of GaspA, and thus one should
     // be able to prove the invariant that f_A is *only* invoked from
     // from an instance of GaspA (either via the GaspA drop
-    // implementation or the E drop implementaton). Yet the old (bad)
+    // implementation or the E drop implementation). Yet the old (bad)
     // behavior allowed a call to f_A to leak in while we are tearing
     // down a value of type GaspB.
 }
diff --git a/src/test/ui/issues/issue-25901.stderr b/src/test/ui/issues/issue-25901.stderr
index e933745c4..c6c80e41c 100644
--- a/src/test/ui/issues/issue-25901.stderr
+++ b/src/test/ui/issues/issue-25901.stderr
@@ -16,6 +16,7 @@ note: impl defined here, but it is not `const`
 LL | impl Deref for A {
    | ^^^^^^^^^^^^^^^^
    = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-26217.stderr b/src/test/ui/issues/issue-26217.stderr
index c7601caac..73c772205 100644
--- a/src/test/ui/issues/issue-26217.stderr
+++ b/src/test/ui/issues/issue-26217.stderr
@@ -5,6 +5,12 @@ LL | fn bar<'a>() {
    |        -- lifetime `'a` defined here
 LL |     foo::<&'a i32>();
    |     ^^^^^^^^^^^^^^ requires that `'a` must outlive `'static`
+   |
+note: due to current limitations in the borrow checker, this implies a `'static` lifetime
+  --> $DIR/issue-26217.rs:1:30
+   |
+LL | fn foo<T>() where for<'a> T: 'a {}
+   |                              ^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-2708.rs b/src/test/ui/issues/issue-2708.rs
index abd5e9507..4e53b9d14 100644
--- a/src/test/ui/issues/issue-2708.rs
+++ b/src/test/ui/issues/issue-2708.rs
@@ -4,7 +4,7 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
+
 
 struct Font {
     fontbuf: usize,
@@ -26,5 +26,5 @@ fn Font() -> Font {
 }
 
 pub fn main() {
-    let _f: Box<_> = box Font();
+    let _f: Box<_> = Box::new(Font());
 }
diff --git a/src/test/ui/issues/issue-2734.rs b/src/test/ui/issues/issue-2734.rs
index d449f6449..df4f394dc 100644
--- a/src/test/ui/issues/issue-2734.rs
+++ b/src/test/ui/issues/issue-2734.rs
@@ -4,21 +4,19 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 trait hax {
     fn dummy(&self) { }
 }
 impl<A> hax for A { }
 
 fn perform_hax<T: 'static>(x: Box<T>) -> Box<dyn hax+'static> {
-    box x as Box<dyn hax+'static>
+    Box::new(x) as Box<dyn hax+'static>
 }
 
 fn deadcode() {
-    perform_hax(box "deadcode".to_string());
+    perform_hax(Box::new("deadcode".to_string()));
 }
 
 pub fn main() {
-    let _ = perform_hax(box 42);
+    let _ = perform_hax(Box::new(42));
 }
diff --git a/src/test/ui/issues/issue-2735.rs b/src/test/ui/issues/issue-2735.rs
index 794c7d4ed..20d3949a9 100644
--- a/src/test/ui/issues/issue-2735.rs
+++ b/src/test/ui/issues/issue-2735.rs
@@ -4,21 +4,19 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 trait hax {
     fn dummy(&self) { }
 }
 impl<A> hax for A { }
 
 fn perform_hax<T: 'static>(x: Box<T>) -> Box<dyn hax+'static> {
-    box x as Box<dyn hax+'static>
+    Box::new(x) as Box<dyn hax+'static>
 }
 
 fn deadcode() {
-    perform_hax(box "deadcode".to_string());
+    perform_hax(Box::new("deadcode".to_string()));
 }
 
 pub fn main() {
-    perform_hax(box 42);
+    perform_hax(Box::new(42));
 }
diff --git a/src/test/ui/issues/issue-28344.stderr b/src/test/ui/issues/issue-28344.stderr
index b1d1c01b2..85a8698af 100644
--- a/src/test/ui/issues/issue-28344.stderr
+++ b/src/test/ui/issues/issue-28344.stderr
@@ -25,7 +25,7 @@ LL |     let x: u8 = BitXor::bitor(0 as u8, 0 as u8);
    |                         ^^^^^
    |                         |
    |                         function or associated item not found in `dyn BitXor<_>`
-   |                         help: there is an associated function with a similar name: `bitxor`
+   |                         help: there is a method with a similar name: `bitxor`
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-28344.rs:10:13
@@ -53,7 +53,7 @@ LL |     let g = BitXor::bitor;
    |                     ^^^^^
    |                     |
    |                     function or associated item not found in `dyn BitXor<_>`
-   |                     help: there is an associated function with a similar name: `bitxor`
+   |                     help: there is a method with a similar name: `bitxor`
 
 error: aborting due to 4 previous errors; 2 warnings emitted
 
diff --git a/src/test/ui/issues/issue-2935.rs b/src/test/ui/issues/issue-2935.rs
index 11641ca73..37f818199 100644
--- a/src/test/ui/issues/issue-2935.rs
+++ b/src/test/ui/issues/issue-2935.rs
@@ -1,7 +1,6 @@
 // run-pass
 #![allow(dead_code)]
 #![allow(non_camel_case_types)]
-#![feature(box_syntax)]
 
 //type t = { a: isize };
 // type t = { a: bool };
@@ -20,7 +19,7 @@ pub fn main() {
   //   let y = box ({a: 4});
   //    let z = box ({a: 4} as it);
   //    let z = box ({a: true} as it);
-    let z: Box<_> = box (box true as Box<dyn it>);
+    let z: Box<_> = Box::new(Box::new(true) as Box<dyn it>);
     //  x.f();
     // y.f();
     // (*z).f();
diff --git a/src/test/ui/issues/issue-3026.rs b/src/test/ui/issues/issue-3026.rs
index 1dea8134f..4619a3fe7 100644
--- a/src/test/ui/issues/issue-3026.rs
+++ b/src/test/ui/issues/issue-3026.rs
@@ -1,13 +1,11 @@
 // run-pass
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 use std::collections::HashMap;
 
 pub fn main() {
     let x: Box<_>;
     let mut buggy_map: HashMap<usize, &usize> = HashMap::new();
-    x = box 1;
+    x = Box::new(1);
     buggy_map.insert(42, &*x);
 }
diff --git a/src/test/ui/issues/issue-31173.rs b/src/test/ui/issues/issue-31173.rs
index 48061ae54..04efa2718 100644
--- a/src/test/ui/issues/issue-31173.rs
+++ b/src/test/ui/issues/issue-31173.rs
@@ -3,12 +3,13 @@ use std::vec::IntoIter;
 pub fn get_tok(it: &mut IntoIter<u8>) {
     let mut found_e = false;
 
-    let temp: Vec<u8> = it.take_while(|&x| {
-        found_e = true;
-        false
-    })
+    let temp: Vec<u8> = it
+        //~^ ERROR to be an iterator that yields `&_`, but it yields `u8`
+        .take_while(|&x| {
+            found_e = true;
+            false
+        })
         .cloned()
-        //~^ ERROR type mismatch resolving
         .collect(); //~ ERROR the method
 }
 
diff --git a/src/test/ui/issues/issue-31173.stderr b/src/test/ui/issues/issue-31173.stderr
index 68337a715..e3334eef3 100644
--- a/src/test/ui/issues/issue-31173.stderr
+++ b/src/test/ui/issues/issue-31173.stderr
@@ -1,8 +1,16 @@
-error[E0271]: type mismatch resolving `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]> as Iterator>::Item == &_`
-  --> $DIR/issue-31173.rs:10:10
-   |
-LL |         .cloned()
-   |          ^^^^^^ expected reference, found `u8`
+error[E0271]: expected `TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>` to be an iterator that yields `&_`, but it yields `u8`
+  --> $DIR/issue-31173.rs:6:25
+   |
+LL |       let temp: Vec<u8> = it
+   |  _________________________^
+LL | |
+LL | |         .take_while(|&x| {
+LL | |             found_e = true;
+LL | |             false
+LL | |         })
+   | |__________^ expected reference, found `u8`
+LL |           .cloned()
+   |            ------ required by a bound introduced by this call
    |
    = note: expected reference `&_`
                    found type `u8`
@@ -12,27 +20,27 @@ note: required by a bound in `cloned`
 LL |         Self: Sized + Iterator<Item = &'a T>,
    |                                ^^^^^^^^^^^^ required by this bound in `cloned`
 
-error[E0599]: the method `collect` exists for struct `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>`, but its trait bounds were not satisfied
-  --> $DIR/issue-31173.rs:12:10
+error[E0599]: the method `collect` exists for struct `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>`, but its trait bounds were not satisfied
+  --> $DIR/issue-31173.rs:13:10
    |
 LL |         .collect();
-   |          ^^^^^^^ method cannot be called on `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>` due to unsatisfied trait bounds
-   |
-  ::: $SRC_DIR/core/src/iter/adapters/cloned.rs:LL:COL
-   |
-LL | pub struct Cloned<I> {
-   | -------------------- doesn't satisfy `_: Iterator`
+   |          ^^^^^^^ method cannot be called on `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>` due to unsatisfied trait bounds
    |
   ::: $SRC_DIR/core/src/iter/adapters/take_while.rs:LL:COL
    |
 LL | pub struct TakeWhile<I, P> {
    | -------------------------- doesn't satisfy `<_ as Iterator>::Item = &_`
    |
+  ::: $SRC_DIR/core/src/iter/adapters/cloned.rs:LL:COL
+   |
+LL | pub struct Cloned<I> {
+   | -------------------- doesn't satisfy `_: Iterator`
+   |
    = note: the following trait bounds were not satisfied:
-           `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]> as Iterator>::Item = &_`
-           which is required by `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>: Iterator`
-           `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>: Iterator`
-           which is required by `&mut Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>: Iterator`
+           `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]> as Iterator>::Item = &_`
+           which is required by `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>: Iterator`
+           `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>: Iterator`
+           which is required by `&mut Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>: Iterator`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/issues/issue-3121.rs b/src/test/ui/issues/issue-3121.rs
index f7bbfa9f6..4bf5b9b60 100644
--- a/src/test/ui/issues/issue-3121.rs
+++ b/src/test/ui/issues/issue-3121.rs
@@ -1,7 +1,6 @@
 // run-pass
 #![allow(dead_code)]
 #![allow(non_camel_case_types)]
-#![feature(box_syntax)]
 
 #[derive(Copy, Clone)]
 enum side { mayo, catsup, vinegar }
@@ -21,5 +20,5 @@ fn foo(m: Box<meal>, cond: bool) {
 }
 
 pub fn main() {
-    foo(box meal::for_here(order::hamburger), true)
+    foo(Box::new(meal::for_here(order::hamburger)), true)
 }
diff --git a/src/test/ui/issues/issue-3214.stderr b/src/test/ui/issues/issue-3214.stderr
index 4d8eb6360..aa0b5ce64 100644
--- a/src/test/ui/issues/issue-3214.stderr
+++ b/src/test/ui/issues/issue-3214.stderr
@@ -2,10 +2,9 @@ error[E0401]: can't use generic parameters from outer function
   --> $DIR/issue-3214.rs:3:12
    |
 LL | fn foo<T>() {
-   |    --- - type parameter from outer function
-   |    |
-   |    try adding a local generic parameter in this method instead
+   |        - type parameter from outer function
 LL |     struct Foo {
+   |               - help: try using a local generic parameter instead: `<T>`
 LL |         x: T,
    |            ^ use of generic parameter from outer function
 
diff --git a/src/test/ui/issues/issue-32709.stderr b/src/test/ui/issues/issue-32709.stderr
index 112cb3359..1d595ca56 100644
--- a/src/test/ui/issues/issue-32709.stderr
+++ b/src/test/ui/issues/issue-32709.stderr
@@ -10,7 +10,7 @@ LL |     Err(5)?;
    = help: the following other types implement trait `FromResidual<R>`:
              <Result<T, F> as FromResidual<Result<Infallible, E>>>
              <Result<T, F> as FromResidual<Yeet<E>>>
-   = note: required because of the requirements on the impl of `FromResidual<Result<Infallible, {integer}>>` for `Result<i32, ()>`
+   = note: required for `Result<i32, ()>` to implement `FromResidual<Result<Infallible, {integer}>>`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-3290.rs b/src/test/ui/issues/issue-3290.rs
index 840c7ff83..7014d517f 100644
--- a/src/test/ui/issues/issue-3290.rs
+++ b/src/test/ui/issues/issue-3290.rs
@@ -1,9 +1,8 @@
 // run-pass
-#![feature(box_syntax)]
 #![allow(dead_code)]
 
 pub fn main() {
-   let mut x: Box<_> = box 3;
+   let mut x: Box<_> = Box::new(3);
    x = x;
    assert_eq!(*x, 3);
 }
diff --git a/src/test/ui/issues/issue-33941.rs b/src/test/ui/issues/issue-33941.rs
index a1213623e..8430e85df 100644
--- a/src/test/ui/issues/issue-33941.rs
+++ b/src/test/ui/issues/issue-33941.rs
@@ -3,7 +3,7 @@
 use std::collections::HashMap;
 
 fn main() {
-    for _ in HashMap::new().iter().cloned() {} //~ ERROR type mismatch
-    //~^ ERROR type mismatch
-    //~| ERROR type mismatch
+    for _ in HashMap::new().iter().cloned() {} //~ ERROR expected `std::collections::hash_map::Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
+    //~^ ERROR expected `std::collections::hash_map::Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
+    //~| ERROR expected `std::collections::hash_map::Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
 }
diff --git a/src/test/ui/issues/issue-33941.stderr b/src/test/ui/issues/issue-33941.stderr
index e1ce6eed9..691b8f88f 100644
--- a/src/test/ui/issues/issue-33941.stderr
+++ b/src/test/ui/issues/issue-33941.stderr
@@ -1,8 +1,10 @@
-error[E0271]: type mismatch resolving `<std::collections::hash_map::Iter<'_, _, _> as Iterator>::Item == &_`
-  --> $DIR/issue-33941.rs:6:36
+error[E0271]: expected `std::collections::hash_map::Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
+  --> $DIR/issue-33941.rs:6:14
    |
 LL |     for _ in HashMap::new().iter().cloned() {}
-   |                                    ^^^^^^ expected reference, found tuple
+   |              ^^^^^^^^^^^^^^^^^^^^^ ------ required by a bound introduced by this call
+   |              |
+   |              expected reference, found tuple
    |
    = note: expected reference `&_`
                   found tuple `(&_, &_)`
@@ -12,7 +14,7 @@ note: required by a bound in `cloned`
 LL |         Self: Sized + Iterator<Item = &'a T>,
    |                                ^^^^^^^^^^^^ required by this bound in `cloned`
 
-error[E0271]: type mismatch resolving `<std::collections::hash_map::Iter<'_, _, _> as Iterator>::Item == &_`
+error[E0271]: expected `std::collections::hash_map::Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
   --> $DIR/issue-33941.rs:6:14
    |
 LL |     for _ in HashMap::new().iter().cloned() {}
@@ -20,10 +22,10 @@ LL |     for _ in HashMap::new().iter().cloned() {}
    |
    = note:  expected tuple `(&_, &_)`
            found reference `&_`
-   = note: required because of the requirements on the impl of `Iterator` for `Cloned<std::collections::hash_map::Iter<'_, _, _>>`
-   = note: required because of the requirements on the impl of `IntoIterator` for `Cloned<std::collections::hash_map::Iter<'_, _, _>>`
+   = note: required for `Cloned<std::collections::hash_map::Iter<'_, _, _>>` to implement `Iterator`
+   = note: required for `Cloned<std::collections::hash_map::Iter<'_, _, _>>` to implement `IntoIterator`
 
-error[E0271]: type mismatch resolving `<std::collections::hash_map::Iter<'_, _, _> as Iterator>::Item == &_`
+error[E0271]: expected `std::collections::hash_map::Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
   --> $DIR/issue-33941.rs:6:14
    |
 LL |     for _ in HashMap::new().iter().cloned() {}
@@ -31,7 +33,7 @@ LL |     for _ in HashMap::new().iter().cloned() {}
    |
    = note:  expected tuple `(&_, &_)`
            found reference `&_`
-   = note: required because of the requirements on the impl of `Iterator` for `Cloned<std::collections::hash_map::Iter<'_, _, _>>`
+   = note: required for `Cloned<std::collections::hash_map::Iter<'_, _, _>>` to implement `Iterator`
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/issues/issue-34334.stderr b/src/test/ui/issues/issue-34334.stderr
index 48ae2df69..72082f0cd 100644
--- a/src/test/ui/issues/issue-34334.stderr
+++ b/src/test/ui/issues/issue-34334.stderr
@@ -13,10 +13,12 @@ LL |     let sr: Vec<(u32, _, _)> = vec![];
    |                            +
 
 error[E0277]: a value of type `Vec<(u32, _, _)>` cannot be built from an iterator over elements of type `()`
-  --> $DIR/issue-34334.rs:5:87
+  --> $DIR/issue-34334.rs:5:33
    |
 LL |     let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect();
-   |                                                                                       ^^^^^^^ value of type `Vec<(u32, _, _)>` cannot be built from `std::iter::Iterator<Item=()>`
+   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |                                 |
+   |                                 value of type `Vec<(u32, _, _)>` cannot be built from `std::iter::Iterator<Item=()>`
    |
    = help: the trait `FromIterator<()>` is not implemented for `Vec<(u32, _, _)>`
    = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
diff --git a/src/test/ui/issues/issue-34349.stderr b/src/test/ui/issues/issue-34349.stderr
index d0b51961b..8e9a16619 100644
--- a/src/test/ui/issues/issue-34349.stderr
+++ b/src/test/ui/issues/issue-34349.stderr
@@ -7,7 +7,15 @@ LL |         farewell.push_str("!!!");
    |         -------- closure is `FnMut` because it mutates the variable `farewell` here
 ...
 LL |     apply(diary);
-   |     ----- the requirement to implement `Fn` derives from here
+   |     ----- ----- the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `apply`
+  --> $DIR/issue-34349.rs:11:32
+   |
+LL |     fn apply<F>(f: F) where F: Fn() {
+   |                                ^^^^ required by this bound in `apply`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-3447.rs b/src/test/ui/issues/issue-3447.rs
index 1e329d152..ee5b22778 100644
--- a/src/test/ui/issues/issue-3447.rs
+++ b/src/test/ui/issues/issue-3447.rs
@@ -2,7 +2,6 @@
 #![allow(dead_code)]
 #![allow(non_snake_case)]
 #![allow(non_camel_case_types)]
-#![feature(box_syntax)]
 
 use std::cell::RefCell;
 
@@ -20,7 +19,7 @@ impl<T:'static> list<T> {
             next: None
         };
 
-        self.next = Some(box RefCell::new(newList));
+        self.next = Some(Box::new(RefCell::new(newList)));
     }
 }
 
diff --git a/src/test/ui/issues/issue-35241.stderr b/src/test/ui/issues/issue-35241.stderr
index a66289a1c..9ee7654a0 100644
--- a/src/test/ui/issues/issue-35241.stderr
+++ b/src/test/ui/issues/issue-35241.stderr
@@ -13,8 +13,8 @@ LL | fn test() -> Foo { Foo }
              found fn item `fn(u32) -> Foo {Foo}`
 help: use parentheses to instantiate this tuple struct
    |
-LL | fn test() -> Foo { Foo(_) }
-   |                       +++
+LL | fn test() -> Foo { Foo(/* u32 */) }
+   |                       +++++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-35570.rs b/src/test/ui/issues/issue-35570.rs
index 42cef9a47..a2b0222d4 100644
--- a/src/test/ui/issues/issue-35570.rs
+++ b/src/test/ui/issues/issue-35570.rs
@@ -6,7 +6,8 @@ trait Trait2<'a> {
 }
 
 fn _ice(param: Box<dyn for <'a> Trait1<<() as Trait2<'a>>::Ty>>) {
-//~^ the trait bound `for<'a> (): Trait2<'a>` is not satisfied
+    //~^ ERROR the trait bound `for<'a> (): Trait2<'a>` is not satisfied
+    //~| ERROR the trait bound `for<'a> (): Trait2<'a>` is not satisfied
     let _e: (usize, usize) = unsafe{mem::transmute(param)};
 }
 
diff --git a/src/test/ui/issues/issue-35570.stderr b/src/test/ui/issues/issue-35570.stderr
index 2697d46bd..ebc40f678 100644
--- a/src/test/ui/issues/issue-35570.stderr
+++ b/src/test/ui/issues/issue-35570.stderr
@@ -1,9 +1,19 @@
 error[E0277]: the trait bound `for<'a> (): Trait2<'a>` is not satisfied
+  --> $DIR/issue-35570.rs:8:1
+   |
+LL | / fn _ice(param: Box<dyn for <'a> Trait1<<() as Trait2<'a>>::Ty>>) {
+LL | |
+LL | |
+LL | |     let _e: (usize, usize) = unsafe{mem::transmute(param)};
+LL | | }
+   | |_^ the trait `for<'a> Trait2<'a>` is not implemented for `()`
+
+error[E0277]: the trait bound `for<'a> (): Trait2<'a>` is not satisfied
   --> $DIR/issue-35570.rs:8:40
    |
 LL | fn _ice(param: Box<dyn for <'a> Trait1<<() as Trait2<'a>>::Ty>>) {
    |                                        ^^^^^^^^^^^^^^^^^^^^^^ the trait `for<'a> Trait2<'a>` is not implemented for `()`
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/issues/issue-3794.rs b/src/test/ui/issues/issue-3794.rs
index 1809e822c..b1f028fbc 100644
--- a/src/test/ui/issues/issue-3794.rs
+++ b/src/test/ui/issues/issue-3794.rs
@@ -1,5 +1,4 @@
 // run-pass
-#![feature(box_syntax)]
 #![allow(dead_code)]
 
 trait T {
@@ -26,7 +25,7 @@ fn print_s(s: &S) {
 }
 
 pub fn main() {
-    let s: Box<S> = box S { s: 5 };
+    let s: Box<S> = Box::new(S { s: 5 });
     print_s(&*s);
     let t: Box<dyn T> = s as Box<dyn T>;
     print_t(&*t);
diff --git a/src/test/ui/issues/issue-3878.rs b/src/test/ui/issues/issue-3878.rs
index a121f0ba8..6de3405af 100644
--- a/src/test/ui/issues/issue-3878.rs
+++ b/src/test/ui/issues/issue-3878.rs
@@ -2,9 +2,8 @@
 // pretty-expanded FIXME #23616
 
 #![allow(path_statements)]
-#![feature(box_syntax)]
 
 pub fn main() {
-    let y: Box<_> = box 1;
+    let y: Box<_> = Box::new(1);
     y;
 }
diff --git a/src/test/ui/issues/issue-38821.stderr b/src/test/ui/issues/issue-38821.stderr
index cdf1f0dfc..9abd2436b 100644
--- a/src/test/ui/issues/issue-38821.stderr
+++ b/src/test/ui/issues/issue-38821.stderr
@@ -4,7 +4,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
 LL | #[derive(Debug, Copy, Clone)]
    |                 ^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
    |
-note: required because of the requirements on the impl of `IntoNullable` for `<Col as Expression>::SqlType`
+note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
    |
 LL | impl<T: NotNull> IntoNullable for T {
diff --git a/src/test/ui/issues/issue-39970.stderr b/src/test/ui/issues/issue-39970.stderr
index 1f64a90bc..774575d1d 100644
--- a/src/test/ui/issues/issue-39970.stderr
+++ b/src/test/ui/issues/issue-39970.stderr
@@ -9,7 +9,7 @@ note: expected this to be `()`
    |
 LL |     type Element = &'a ();
    |                    ^^^^^^
-note: required because of the requirements on the impl of `Visit` for `()`
+note: required for `()` to implement `Visit`
   --> $DIR/issue-39970.rs:13:6
    |
 LL | impl Visit for () where
diff --git a/src/test/ui/issues/issue-40510-3.stderr b/src/test/ui/issues/issue-40510-3.stderr
index 22186ba9a..eb077415e 100644
--- a/src/test/ui/issues/issue-40510-3.stderr
+++ b/src/test/ui/issues/issue-40510-3.stderr
@@ -14,6 +14,10 @@ LL | |         }
    |
    = note: `FnMut` closures only have access to their captured variables while they are executing...
    = note: ...therefore, they cannot allow references to captured variables to escape
+help: consider adding 'move' keyword before the nested closure
+   |
+LL |         move || {
+   |         ++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-40827.stderr b/src/test/ui/issues/issue-40827.stderr
index 11c23e5b6..7f5c578ae 100644
--- a/src/test/ui/issues/issue-40827.stderr
+++ b/src/test/ui/issues/issue-40827.stderr
@@ -12,7 +12,7 @@ note: required because it appears within the type `Bar`
    |
 LL | enum Bar {
    |      ^^^
-   = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
+   = note: required for `Arc<Bar>` to implement `Send`
 note: required because it appears within the type `Foo`
   --> $DIR/issue-40827.rs:4:8
    |
@@ -38,7 +38,7 @@ note: required because it appears within the type `Bar`
    |
 LL | enum Bar {
    |      ^^^
-   = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
+   = note: required for `Arc<Bar>` to implement `Send`
 note: required because it appears within the type `Foo`
   --> $DIR/issue-40827.rs:4:8
    |
diff --git a/src/test/ui/issues/issue-41139.stderr b/src/test/ui/issues/issue-41139.stderr
index 48b22bca2..97492e6e0 100644
--- a/src/test/ui/issues/issue-41139.stderr
+++ b/src/test/ui/issues/issue-41139.stderr
@@ -5,9 +5,7 @@ LL | fn get_function<'a>() -> &'a dyn Fn() -> dyn Trait {
    | -------------------------------------------------- `get_function` defined here returns `&dyn Fn() -> (dyn Trait + 'static)`
 ...
 LL |     let t: &dyn Trait = &get_function()();
-   |                          ^^^^^^^^^^^^^^--
-   |                          |
-   |                          call expression requires function
+   |                          ^^^^^^^^^^^^^^ this trait object returns an unsized value `(dyn Trait + 'static)`, so it cannot be called
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-41726.stderr b/src/test/ui/issues/issue-41726.stderr
index 22631e7c2..b05c1fb14 100644
--- a/src/test/ui/issues/issue-41726.stderr
+++ b/src/test/ui/issues/issue-41726.stderr
@@ -5,6 +5,10 @@ LL |         things[src.as_str()].sort();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot borrow as mutable
    |
    = help: trait `IndexMut` is required to modify indexed content, but it is not implemented for `HashMap<String, Vec<String>>`
+help: to modify a `HashMap<String, Vec<String>>` use `.get_mut()`
+   |
+LL |         things.get_mut(src.as_str()).map(|val| val.sort());
+   |               ~~~~~~~~~            ~~~~~~~~~~~~~~~       +
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-41974.stderr b/src/test/ui/issues/issue-41974.stderr
index fcbb40140..e249db9df 100644
--- a/src/test/ui/issues/issue-41974.stderr
+++ b/src/test/ui/issues/issue-41974.stderr
@@ -7,11 +7,11 @@ LL | impl<T> Drop for T where T: A {
    = note: implementing a foreign trait is only possible if at least one of the types for which it is implemented is local
    = note: only traits defined in the current crate can be implemented for a type parameter
 
-error[E0120]: the `Drop` trait may only be implemented for structs, enums, and unions
+error[E0120]: the `Drop` trait may only be implemented for local structs, enums, and unions
   --> $DIR/issue-41974.rs:7:18
    |
 LL | impl<T> Drop for T where T: A {
-   |                  ^ must be a struct, enum, or union
+   |                  ^ must be a struct, enum, or union in the current crate
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/issues/issue-43988.stderr b/src/test/ui/issues/issue-43988.stderr
index 03aa37f52..02c5dd5bf 100644
--- a/src/test/ui/issues/issue-43988.stderr
+++ b/src/test/ui/issues/issue-43988.stderr
@@ -31,12 +31,16 @@ error[E0552]: unrecognized representation hint
    |
 LL |     #[repr(nothing)]
    |            ^^^^^^^
+   |
+   = help: valid reprs are `C`, `align`, `packed`, `transparent`, `simd`, `i8`, `u8`, `i16`, `u16`, `i32`, `u32`, `i64`, `u64`, `i128`, `u128`, `isize`, `usize`
 
 error[E0552]: unrecognized representation hint
   --> $DIR/issue-43988.rs:18:12
    |
 LL |     #[repr(something_not_real)]
    |            ^^^^^^^^^^^^^^^^^^
+   |
+   = help: valid reprs are `C`, `align`, `packed`, `transparent`, `simd`, `i8`, `u8`, `i16`, `u16`, `i32`, `u32`, `i64`, `u64`, `i128`, `u128`, `isize`, `usize`
 
 error[E0518]: attribute should be applied to function or closure
   --> $DIR/issue-43988.rs:30:5
diff --git a/src/test/ui/issues/issue-47511.stderr b/src/test/ui/issues/issue-47511.stderr
index 5b84f7ed6..9998ee0e8 100644
--- a/src/test/ui/issues/issue-47511.stderr
+++ b/src/test/ui/issues/issue-47511.stderr
@@ -4,7 +4,8 @@ error[E0581]: return type references an anonymous lifetime, which is not constra
 LL | fn f(_: X) -> X {
    |               ^
    |
-   = note: lifetimes appearing in an associated type are not considered constrained
+   = note: lifetimes appearing in an associated or opaque type are not considered constrained
+   = note: consider introducing a named lifetime parameter
 
 error[E0581]: return type references lifetime `'a`, which is not constrained by the fn input types
   --> $DIR/issue-47511.rs:12:23
diff --git a/src/test/ui/issues/issue-4759.rs b/src/test/ui/issues/issue-4759.rs
index 53785af09..e5b9e2ed5 100644
--- a/src/test/ui/issues/issue-4759.rs
+++ b/src/test/ui/issues/issue-4759.rs
@@ -2,8 +2,6 @@
 // pretty-expanded FIXME #23616
 #![allow(non_shorthand_field_patterns)]
 
-#![feature(box_syntax)]
-
 struct T { a: Box<isize> }
 
 trait U {
@@ -15,6 +13,6 @@ impl U for Box<isize> {
 }
 
 pub fn main() {
-    let T { a: a } = T { a: box 0 };
+    let T { a: a } = T { a: Box::new(0) };
     a.f();
 }
diff --git a/src/test/ui/issues/issue-4935.stderr b/src/test/ui/issues/issue-4935.stderr
index aab19a699..bb45fa083 100644
--- a/src/test/ui/issues/issue-4935.stderr
+++ b/src/test/ui/issues/issue-4935.stderr
@@ -12,7 +12,7 @@ LL | fn foo(a: usize) {}
 help: remove the extra argument
    |
 LL | fn main() { foo(5) }
-   |             ~~~~~~
+   |                ~~~
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-4972.rs b/src/test/ui/issues/issue-4972.rs
index fab258f13..3f1c6f855 100644
--- a/src/test/ui/issues/issue-4972.rs
+++ b/src/test/ui/issues/issue-4972.rs
@@ -1,5 +1,4 @@
 #![feature(box_patterns)]
-#![feature(box_syntax)]
 
 trait MyTrait {
     fn dummy(&self) {}
diff --git a/src/test/ui/issues/issue-4972.stderr b/src/test/ui/issues/issue-4972.stderr
index 40db50278..83daded7e 100644
--- a/src/test/ui/issues/issue-4972.stderr
+++ b/src/test/ui/issues/issue-4972.stderr
@@ -1,5 +1,5 @@
 error[E0033]: type `Box<(dyn MyTrait + 'static)>` cannot be dereferenced
-  --> $DIR/issue-4972.rs:14:25
+  --> $DIR/issue-4972.rs:13:25
    |
 LL |         TraitWrapper::A(box ref map) => map,
    |                         ^^^^^^^^^^^ type `Box<(dyn MyTrait + 'static)>` cannot be dereferenced
diff --git a/src/test/ui/issues/issue-49824.stderr b/src/test/ui/issues/issue-49824.stderr
index 2fec48254..14beadece 100644
--- a/src/test/ui/issues/issue-49824.stderr
+++ b/src/test/ui/issues/issue-49824.stderr
@@ -14,6 +14,10 @@ LL | |         }
    |
    = note: `FnMut` closures only have access to their captured variables while they are executing...
    = note: ...therefore, they cannot allow references to captured variables to escape
+help: consider adding 'move' keyword before the nested closure
+   |
+LL |         move || {
+   |         ++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-5100.rs b/src/test/ui/issues/issue-5100.rs
index 5e926fabe..69ed4b0e4 100644
--- a/src/test/ui/issues/issue-5100.rs
+++ b/src/test/ui/issues/issue-5100.rs
@@ -1,5 +1,5 @@
 #![feature(box_patterns)]
-#![feature(box_syntax)]
+
 
 enum A { B, C }
 
diff --git a/src/test/ui/issues/issue-5192.rs b/src/test/ui/issues/issue-5192.rs
index 5a83d1c2f..e2f835c19 100644
--- a/src/test/ui/issues/issue-5192.rs
+++ b/src/test/ui/issues/issue-5192.rs
@@ -2,8 +2,6 @@
 #![allow(dead_code)]
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 pub trait EventLoop {
     fn dummy(&self) { }
 }
@@ -37,5 +35,5 @@ impl Scheduler {
 }
 
 pub fn main() {
-    let _sched = Scheduler::new(box UvEventLoop::new() as Box<dyn EventLoop>);
+    let _sched = Scheduler::new(Box::new(UvEventLoop::new()) as Box<dyn EventLoop>);
 }
diff --git a/src/test/ui/issues/issue-5439.rs b/src/test/ui/issues/issue-5439.rs
index cd039506f..852b264dc 100644
--- a/src/test/ui/issues/issue-5439.rs
+++ b/src/test/ui/issues/issue-5439.rs
@@ -1,5 +1,3 @@
-#![feature(box_syntax)]
-
 struct Foo {
     foo: isize,
 }
@@ -10,7 +8,7 @@ struct Bar {
 
 impl Bar {
     fn make_foo (&self, i: isize) -> Box<Foo> {
-        return box Foo { nonexistent: self, foo: i }; //~ ERROR: no field named
+        return Box::new(Foo { nonexistent: self, foo: i }); //~ ERROR: no field named
     }
 }
 
diff --git a/src/test/ui/issues/issue-5439.stderr b/src/test/ui/issues/issue-5439.stderr
index bd0cb670b..dc8f8b878 100644
--- a/src/test/ui/issues/issue-5439.stderr
+++ b/src/test/ui/issues/issue-5439.stderr
@@ -1,8 +1,8 @@
 error[E0560]: struct `Foo` has no field named `nonexistent`
-  --> $DIR/issue-5439.rs:13:26
+  --> $DIR/issue-5439.rs:11:31
    |
-LL |         return box Foo { nonexistent: self, foo: i };
-   |                          ^^^^^^^^^^^ `Foo` does not have this field
+LL |         return Box::new(Foo { nonexistent: self, foo: i });
+   |                               ^^^^^^^^^^^ `Foo` does not have this field
    |
    = note: available fields are: `foo`
 
diff --git a/src/test/ui/issues/issue-5666.rs b/src/test/ui/issues/issue-5666.rs
index aa5132778..810895b1b 100644
--- a/src/test/ui/issues/issue-5666.rs
+++ b/src/test/ui/issues/issue-5666.rs
@@ -1,5 +1,4 @@
 // run-pass
-#![feature(box_syntax)]
 
 struct Dog {
     name : String
@@ -17,8 +16,8 @@ impl Barks for Dog {
 
 
 pub fn main() {
-    let snoopy = box Dog{name: "snoopy".to_string()};
-    let bubbles = box Dog{name: "bubbles".to_string()};
+    let snoopy = Box::new(Dog{name: "snoopy".to_string()});
+    let bubbles = Box::new(Dog{name: "bubbles".to_string()});
     let barker = [snoopy as Box<dyn Barks>, bubbles as Box<dyn Barks>];
 
     for pup in &barker {
diff --git a/src/test/ui/issues/issue-5718.rs b/src/test/ui/issues/issue-5718.rs
index 63efec953..f29a1e2a0 100644
--- a/src/test/ui/issues/issue-5718.rs
+++ b/src/test/ui/issues/issue-5718.rs
@@ -1,14 +1,12 @@
 // run-pass
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 struct Element;
 
 macro_rules! foo {
     ($tag: expr, $string: expr) => {
         if $tag == $string {
-            let element: Box<_> = box Element;
+            let element: Box<_> = Box::new(Element);
             unsafe {
                 return std::mem::transmute::<_, usize>(element);
             }
diff --git a/src/test/ui/issues/issue-57362-1.stderr b/src/test/ui/issues/issue-57362-1.stderr
index 8e19f1400..b10273f14 100644
--- a/src/test/ui/issues/issue-57362-1.stderr
+++ b/src/test/ui/issues/issue-57362-1.stderr
@@ -2,9 +2,7 @@ error[E0599]: no method named `f` found for fn pointer `fn(&u8)` in the current
   --> $DIR/issue-57362-1.rs:20:7
    |
 LL |     a.f();
-   |     - ^ method not found in `fn(&u8)`
-   |     |
-   |     this is a function, perhaps you wish to call it
+   |       ^ method not found in `fn(&u8)`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Trait` defines an item `f`, perhaps you need to implement it
diff --git a/src/test/ui/issues/issue-5884.rs b/src/test/ui/issues/issue-5884.rs
index 2f64342a6..991c52321 100644
--- a/src/test/ui/issues/issue-5884.rs
+++ b/src/test/ui/issues/issue-5884.rs
@@ -2,8 +2,6 @@
 #![allow(dead_code)]
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 pub struct Foo {
     a: isize,
 }
@@ -14,7 +12,7 @@ struct Bar<'a> {
 }
 
 fn check(a: Box<Foo>) {
-    let _ic = Bar{ b: &*a, a: box None };
+    let _ic = Bar{ b: &*a, a: Box::new(None) };
 }
 
 pub fn main(){}
diff --git a/src/test/ui/issues/issue-59488.rs b/src/test/ui/issues/issue-59488.rs
index 922b59393..384501e3e 100644
--- a/src/test/ui/issues/issue-59488.rs
+++ b/src/test/ui/issues/issue-59488.rs
@@ -30,4 +30,5 @@ fn main() {
     assert_eq!(Foo::Bar, i);
     //~^ ERROR binary operation `==` cannot be applied to type `fn(usize) -> Foo {Foo::Bar}` [E0369]
     //~| ERROR `fn(usize) -> Foo {Foo::Bar}` doesn't implement `Debug` [E0277]
+    //~| ERROR `fn(usize) -> Foo {Foo::Bar}` doesn't implement `Debug` [E0277]
 }
diff --git a/src/test/ui/issues/issue-59488.stderr b/src/test/ui/issues/issue-59488.stderr
index 7ce3dedaa..08fe0b35e 100644
--- a/src/test/ui/issues/issue-59488.stderr
+++ b/src/test/ui/issues/issue-59488.stderr
@@ -6,7 +6,7 @@ LL |     foo > 12;
    |     |
    |     fn() -> i32 {foo}
    |
-help: you might have forgotten to call this function
+help: use parentheses to call this function
    |
 LL |     foo() > 12;
    |        ++
@@ -28,10 +28,10 @@ LL |     bar > 13;
    |     |
    |     fn(i64) -> i64 {bar}
    |
-help: you might have forgotten to call this function
+help: use parentheses to call this function
    |
-LL |     bar( /* arguments */ ) > 13;
-   |        +++++++++++++++++++
+LL |     bar(/* i64 */) > 13;
+   |        +++++++++++
 
 error[E0308]: mismatched types
   --> $DIR/issue-59488.rs:18:11
@@ -50,14 +50,10 @@ LL |     foo > foo;
    |     |
    |     fn() -> i32 {foo}
    |
-help: you might have forgotten to call this function
+help: use parentheses to call these
    |
-LL |     foo() > foo;
-   |        ++
-help: you might have forgotten to call this function
-   |
-LL |     foo > foo();
-   |              ++
+LL |     foo() > foo();
+   |        ++      ++
 
 error[E0369]: binary operation `>` cannot be applied to type `fn() -> i32 {foo}`
   --> $DIR/issue-59488.rs:25:9
@@ -93,7 +89,26 @@ error[E0277]: `fn(usize) -> Foo {Foo::Bar}` doesn't implement `Debug`
 LL |     assert_eq!(Foo::Bar, i);
    |     ^^^^^^^^^^^^^^^^^^^^^^^ `fn(usize) -> Foo {Foo::Bar}` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
-   = help: the trait `Debug` is not implemented for `fn(usize) -> Foo {Foo::Bar}`
+   = help: the trait `Debug` is not implemented for fn item `fn(usize) -> Foo {Foo::Bar}`
+   = help: the following other types implement trait `Debug`:
+             extern "C" fn() -> Ret
+             extern "C" fn(A, B) -> Ret
+             extern "C" fn(A, B, ...) -> Ret
+             extern "C" fn(A, B, C) -> Ret
+             extern "C" fn(A, B, C, ...) -> Ret
+             extern "C" fn(A, B, C, D) -> Ret
+             extern "C" fn(A, B, C, D, ...) -> Ret
+             extern "C" fn(A, B, C, D, E) -> Ret
+           and 68 others
+   = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `fn(usize) -> Foo {Foo::Bar}` doesn't implement `Debug`
+  --> $DIR/issue-59488.rs:30:5
+   |
+LL |     assert_eq!(Foo::Bar, i);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^ `fn(usize) -> Foo {Foo::Bar}` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |
+   = help: the trait `Debug` is not implemented for fn item `fn(usize) -> Foo {Foo::Bar}`
    = help: the following other types implement trait `Debug`:
              extern "C" fn() -> Ret
              extern "C" fn(A, B) -> Ret
@@ -106,7 +121,7 @@ LL |     assert_eq!(Foo::Bar, i);
            and 68 others
    = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 9 previous errors
+error: aborting due to 10 previous errors
 
 Some errors have detailed explanations: E0277, E0308, E0369.
 For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/issues/issue-5997-enum.stderr b/src/test/ui/issues/issue-5997-enum.stderr
index 1c58b9c39..3a79215d3 100644
--- a/src/test/ui/issues/issue-5997-enum.stderr
+++ b/src/test/ui/issues/issue-5997-enum.stderr
@@ -2,11 +2,11 @@ error[E0401]: can't use generic parameters from outer function
   --> $DIR/issue-5997-enum.rs:2:16
    |
 LL | fn f<Z>() -> bool {
-   |    - - type parameter from outer function
-   |    |
-   |    try adding a local generic parameter in this method instead
+   |      - type parameter from outer function
 LL |     enum E { V(Z) }
-   |                ^ use of generic parameter from outer function
+   |           -    ^ use of generic parameter from outer function
+   |           |
+   |           help: try using a local generic parameter instead: `<Z>`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-5997-struct.stderr b/src/test/ui/issues/issue-5997-struct.stderr
index 5b388d16d..d2e97f767 100644
--- a/src/test/ui/issues/issue-5997-struct.stderr
+++ b/src/test/ui/issues/issue-5997-struct.stderr
@@ -2,11 +2,11 @@ error[E0401]: can't use generic parameters from outer function
   --> $DIR/issue-5997-struct.rs:2:14
    |
 LL | fn f<T>() -> bool {
-   |    - - type parameter from outer function
-   |    |
-   |    try adding a local generic parameter in this method instead
+   |      - type parameter from outer function
 LL |     struct S(T);
-   |              ^ use of generic parameter from outer function
+   |             -^ use of generic parameter from outer function
+   |             |
+   |             help: try using a local generic parameter instead: `<T>`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-60218.stderr b/src/test/ui/issues/issue-60218.stderr
index 870b25014..dd72b6515 100644
--- a/src/test/ui/issues/issue-60218.stderr
+++ b/src/test/ui/issues/issue-60218.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `&u32: Foo` is not satisfied
-  --> $DIR/issue-60218.rs:18:27
+  --> $DIR/issue-60218.rs:18:19
    |
 LL |     trigger_error(vec![], |x: &u32| x)
-   |     -------------         ^^^^^^^^^^^ the trait `Foo` is not implemented for `&u32`
+   |     ------------- ^^^^^^ the trait `Foo` is not implemented for `&u32`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/issues/issue-62480.rs b/src/test/ui/issues/issue-62480.rs
index 5c3be3e64..94a9c2ab8 100644
--- a/src/test/ui/issues/issue-62480.rs
+++ b/src/test/ui/issues/issue-62480.rs
@@ -1,5 +1,3 @@
-#![feature(label_break_value)]
-
 fn main() {
     // This used to ICE during liveness check because `target_id` passed to
     // `propagate_through_expr` would be the closure and not the `loop`, which wouldn't be found in
diff --git a/src/test/ui/issues/issue-62480.stderr b/src/test/ui/issues/issue-62480.stderr
index 17085ef90..db2305370 100644
--- a/src/test/ui/issues/issue-62480.stderr
+++ b/src/test/ui/issues/issue-62480.stderr
@@ -1,5 +1,5 @@
 error[E0767]: use of unreachable label `'a`
-  --> $DIR/issue-62480.rs:8:18
+  --> $DIR/issue-62480.rs:6:18
    |
 LL |     'a: {
    |     -- unreachable label defined here
@@ -9,7 +9,7 @@ LL |         || break 'a
    = note: labels are unreachable through functions, closures, async blocks and modules
 
 error[E0267]: `break` inside of a closure
-  --> $DIR/issue-62480.rs:8:12
+  --> $DIR/issue-62480.rs:6:12
    |
 LL |         || break 'a
    |         -- ^^^^^^^^ cannot `break` inside of a closure
diff --git a/src/test/ui/issues/issue-6318.rs b/src/test/ui/issues/issue-6318.rs
index d8bd83f0d..e5f245f6f 100644
--- a/src/test/ui/issues/issue-6318.rs
+++ b/src/test/ui/issues/issue-6318.rs
@@ -1,8 +1,6 @@
 // run-pass
 // pretty-expanded FIXME #23616
 
-#![feature(box_syntax)]
-
 pub enum Thing {
     A(Box<dyn Foo+'static>)
 }
@@ -16,7 +14,7 @@ pub struct Struct;
 impl Foo for Struct {}
 
 pub fn main() {
-    match Thing::A(box Struct as Box<dyn Foo + 'static>) {
+    match Thing::A(Box::new(Struct) as Box<dyn Foo + 'static>) {
         Thing::A(_a) => 0,
     };
 }
diff --git a/src/test/ui/issues/issue-6557.rs b/src/test/ui/issues/issue-6557.rs
index e066aa529..757e9608f 100644
--- a/src/test/ui/issues/issue-6557.rs
+++ b/src/test/ui/issues/issue-6557.rs
@@ -3,7 +3,6 @@
 // pretty-expanded FIXME #23616
 
 #![feature(box_patterns)]
-#![feature(box_syntax)]
 
 fn foo(box (_x, _y): Box<(isize, isize)>) {}
 
diff --git a/src/test/ui/issues/issue-66706.rs b/src/test/ui/issues/issue-66706.rs
index 4585bcc8c..835fdfae8 100644
--- a/src/test/ui/issues/issue-66706.rs
+++ b/src/test/ui/issues/issue-66706.rs
@@ -2,7 +2,6 @@ fn a() {
     [0; [|_: _ &_| ()].len()]
     //~^ ERROR expected `,`, found `&`
     //~| ERROR type annotations needed
-    //~| ERROR mismatched types
 }
 
 fn b() {
@@ -13,13 +12,11 @@ fn b() {
 fn c() {
     [0; [|&_: _ &_| {}; 0 ].len()]
     //~^ ERROR expected `,`, found `&`
-    //~| ERROR mismatched types
 }
 
 fn d() {
     [0; match [|f @ &ref _| () ] {} ]
     //~^ ERROR expected identifier, found reserved identifier `_`
-    //~| ERROR mismatched types
 }
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-66706.stderr b/src/test/ui/issues/issue-66706.stderr
index 1c55560cb..8a30c0cad 100644
--- a/src/test/ui/issues/issue-66706.stderr
+++ b/src/test/ui/issues/issue-66706.stderr
@@ -7,13 +7,13 @@ LL |     [0; [|_: _ &_| ()].len()]
    |               help: missing `,`
 
 error: expected identifier, found reserved identifier `_`
-  --> $DIR/issue-66706.rs:9:20
+  --> $DIR/issue-66706.rs:8:20
    |
 LL |     [0; [|f @ &ref _| {} ; 0 ].len() ];
    |                    ^ expected identifier, found reserved identifier
 
 error: expected `,`, found `&`
-  --> $DIR/issue-66706.rs:14:17
+  --> $DIR/issue-66706.rs:13:17
    |
 LL |     [0; [|&_: _ &_| {}; 0 ].len()]
    |                -^ expected `,`
@@ -21,7 +21,7 @@ LL |     [0; [|&_: _ &_| {}; 0 ].len()]
    |                help: missing `,`
 
 error: expected identifier, found reserved identifier `_`
-  --> $DIR/issue-66706.rs:20:26
+  --> $DIR/issue-66706.rs:18:26
    |
 LL |     [0; match [|f @ &ref _| () ] {} ]
    |                          ^ expected identifier, found reserved identifier
@@ -32,31 +32,6 @@ error[E0282]: type annotations needed
 LL |     [0; [|_: _ &_| ()].len()]
    |           ^ cannot infer type
 
-error[E0308]: mismatched types
-  --> $DIR/issue-66706.rs:2:5
-   |
-LL | fn a() {
-   |        - help: try adding a return type: `-> [i32; _]`
-LL |     [0; [|_: _ &_| ()].len()]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found array `[{integer}; _]`
-
-error[E0308]: mismatched types
-  --> $DIR/issue-66706.rs:14:5
-   |
-LL | fn c() {
-   |        - help: try adding a return type: `-> [i32; _]`
-LL |     [0; [|&_: _ &_| {}; 0 ].len()]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found array `[{integer}; _]`
-
-error[E0308]: mismatched types
-  --> $DIR/issue-66706.rs:20:5
-   |
-LL | fn d() {
-   |        - help: try adding a return type: `-> [i32; _]`
-LL |     [0; match [|f @ &ref _| () ] {} ]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found array `[{integer}; _]`
-
-error: aborting due to 8 previous errors
+error: aborting due to 5 previous errors
 
-Some errors have detailed explanations: E0282, E0308.
-For more information about an error, try `rustc --explain E0282`.
+For more information about this error, try `rustc --explain E0282`.
diff --git a/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr b/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr
index d6e392516..2de150376 100644
--- a/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr
+++ b/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr
@@ -1,8 +1,10 @@
 error[E0277]: a value of type `Vec<f64>` cannot be built from an iterator over elements of type `&f64`
-  --> $DIR/issue-66923-show-error-for-correct-call.rs:8:39
+  --> $DIR/issue-66923-show-error-for-correct-call.rs:8:24
    |
 LL |     let x2: Vec<f64> = x1.into_iter().collect();
-   |                                       ^^^^^^^ value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
+   |                        ^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |                        |
+   |                        value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
    |
    = help: the trait `FromIterator<&f64>` is not implemented for `Vec<f64>`
    = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
@@ -13,10 +15,12 @@ LL |     fn collect<B: FromIterator<Self::Item>>(self) -> B
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `collect`
 
 error[E0277]: a value of type `Vec<f64>` cannot be built from an iterator over elements of type `&f64`
-  --> $DIR/issue-66923-show-error-for-correct-call.rs:12:29
+  --> $DIR/issue-66923-show-error-for-correct-call.rs:12:14
    |
 LL |     let x3 = x1.into_iter().collect::<Vec<f64>>();
-   |                             ^^^^^^^ value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
+   |              ^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |              |
+   |              value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
    |
    = help: the trait `FromIterator<&f64>` is not implemented for `Vec<f64>`
    = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
diff --git a/src/test/ui/issues/issue-67039-unsound-pin-partialeq.stderr b/src/test/ui/issues/issue-67039-unsound-pin-partialeq.stderr
index 733456a1a..37e2c3bdd 100644
--- a/src/test/ui/issues/issue-67039-unsound-pin-partialeq.stderr
+++ b/src/test/ui/issues/issue-67039-unsound-pin-partialeq.stderr
@@ -6,7 +6,7 @@ LL |     let _ = Pin::new(Apple) == Rc::pin(Apple);
    |
    = note: expected struct `Apple`
               found struct `Rc<Apple>`
-   = note: required because of the requirements on the impl of `PartialEq<Pin<Rc<Apple>>>` for `Pin<Apple>`
+   = note: required for `Pin<Apple>` to implement `PartialEq<Pin<Rc<Apple>>>`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr b/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr
index e5ab65169..f581429a2 100644
--- a/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr
+++ b/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr
@@ -17,10 +17,10 @@ LL | | }
    = note: this error originates in the macro `suite` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: missing type for `const` item
-  --> $DIR/issue-69396-const-no-type-in-macro.rs:4:19
+  --> $DIR/issue-69396-const-no-type-in-macro.rs:4:20
    |
 LL |               const A = "A".$fn();
-   |                     ^ help: provide a type for the constant: `A: usize`
+   |                      ^ help: provide a type for the constant: `: usize`
 ...
 LL | / suite! {
 LL | |     len;
@@ -31,13 +31,13 @@ LL | | }
    = note: this error originates in the macro `suite` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
-  --> $DIR/issue-69396-const-no-type-in-macro.rs:4:19
+  --> $DIR/issue-69396-const-no-type-in-macro.rs:4:20
    |
 LL |               const A = "A".$fn();
-   |                     ^
-   |                     |
-   |                     not allowed in type signatures
-   |                     help: replace with the correct type: `bool`
+   |                      ^
+   |                      |
+   |                      not allowed in type signatures
+   |                      help: replace with the correct type: `bool`
 ...
 LL | / suite! {
 LL | |     len;
diff --git a/src/test/ui/issues/issue-69455.stderr b/src/test/ui/issues/issue-69455.stderr
index b732df764..9d11cf19e 100644
--- a/src/test/ui/issues/issue-69455.stderr
+++ b/src/test/ui/issues/issue-69455.stderr
@@ -16,7 +16,7 @@ error[E0283]: type annotations needed
 LL |     println!("{}", 23u64.test(xs.iter().sum()));
    |                          ----           ^^^ cannot infer type of the type parameter `S` declared on the associated function `sum`
    |                          |
-   |                          type must be known at this point
+   |                          required by a bound introduced by this call
    |
 note: multiple `impl`s satisfying `u64: Test<_>` found
   --> $DIR/issue-69455.rs:11:1
diff --git a/src/test/ui/issues/issue-7013.rs b/src/test/ui/issues/issue-7013.rs
index c1f400b33..1fb01303c 100644
--- a/src/test/ui/issues/issue-7013.rs
+++ b/src/test/ui/issues/issue-7013.rs
@@ -1,5 +1,3 @@
-#![feature(box_syntax)]
-
 use std::cell::RefCell;
 use std::rc::Rc;
 
@@ -23,6 +21,6 @@ struct A {
 }
 
 fn main() {
-    let a = A {v: box B{v: None} as Box<dyn Foo + Send>};
+    let a = A {v: Box::new(B{v: None}) as Box<dyn Foo + Send>};
     //~^ ERROR `Rc<RefCell<A>>` cannot be sent between threads safely
 }
diff --git a/src/test/ui/issues/issue-7013.stderr b/src/test/ui/issues/issue-7013.stderr
index f6cb1cbdc..4575f4dba 100644
--- a/src/test/ui/issues/issue-7013.stderr
+++ b/src/test/ui/issues/issue-7013.stderr
@@ -1,13 +1,13 @@
 error[E0277]: `Rc<RefCell<A>>` cannot be sent between threads safely
-  --> $DIR/issue-7013.rs:26:19
+  --> $DIR/issue-7013.rs:24:19
    |
-LL |     let a = A {v: box B{v: None} as Box<dyn Foo + Send>};
-   |                   ^^^^^^^^^^^^^^ `Rc<RefCell<A>>` cannot be sent between threads safely
+LL |     let a = A {v: Box::new(B{v: None}) as Box<dyn Foo + Send>};
+   |                   ^^^^^^^^^^^^^^^^^^^^ `Rc<RefCell<A>>` cannot be sent between threads safely
    |
    = help: within `B`, the trait `Send` is not implemented for `Rc<RefCell<A>>`
    = note: required because it appears within the type `Option<Rc<RefCell<A>>>`
 note: required because it appears within the type `B`
-  --> $DIR/issue-7013.rs:10:8
+  --> $DIR/issue-7013.rs:8:8
    |
 LL | struct B {
    |        ^
diff --git a/src/test/ui/issues/issue-70724-add_type_neq_err_label-unwrap.stderr b/src/test/ui/issues/issue-70724-add_type_neq_err_label-unwrap.stderr
index c6e6ea1e0..7f29709ce 100644
--- a/src/test/ui/issues/issue-70724-add_type_neq_err_label-unwrap.stderr
+++ b/src/test/ui/issues/issue-70724-add_type_neq_err_label-unwrap.stderr
@@ -8,11 +8,6 @@ LL |     assert_eq!(a, 0);
    |     {integer}
    |
    = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: you might have forgotten to call this function
-  --> $SRC_DIR/core/src/macros/mod.rs:LL:COL
-   |
-LL |                 if !(*left_val() == *right_val) {
-   |                               ++
 
 error[E0308]: mismatched types
   --> $DIR/issue-70724-add_type_neq_err_label-unwrap.rs:6:5
@@ -21,7 +16,7 @@ LL |     assert_eq!(a, 0);
    |     ^^^^^^^^^^^^^^^^ expected fn item, found integer
    |
    = note: expected fn item `fn() -> i32 {a}`
-                 found type `i32`
+                 found type `{integer}`
    = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: `fn() -> i32 {a}` doesn't implement `Debug`
@@ -33,7 +28,7 @@ LL | fn a() -> i32 {
 LL |     assert_eq!(a, 0);
    |     ^^^^^^^^^^^^^^^^ `fn() -> i32 {a}` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
-   = help: the trait `Debug` is not implemented for `fn() -> i32 {a}`
+   = help: the trait `Debug` is not implemented for fn item `fn() -> i32 {a}`
    = help: use parentheses to call the function: `a()`
    = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
diff --git a/src/test/ui/issues/issue-7364.rs b/src/test/ui/issues/issue-7364.rs
index 83c52d286..79642bd41 100644
--- a/src/test/ui/issues/issue-7364.rs
+++ b/src/test/ui/issues/issue-7364.rs
@@ -1,9 +1,7 @@
-#![feature(box_syntax)]
-
 use std::cell::RefCell;
 
 // Regression test for issue 7364
-static boxed: Box<RefCell<isize>> = box RefCell::new(0);
+static boxed: Box<RefCell<isize>> = Box::new(RefCell::new(0));
 //~^ ERROR `RefCell<isize>` cannot be shared between threads safely [E0277]
 
 fn main() { }
diff --git a/src/test/ui/issues/issue-7364.stderr b/src/test/ui/issues/issue-7364.stderr
index f2e80f451..5dc8c2b60 100644
--- a/src/test/ui/issues/issue-7364.stderr
+++ b/src/test/ui/issues/issue-7364.stderr
@@ -1,11 +1,11 @@
 error[E0277]: `RefCell<isize>` cannot be shared between threads safely
-  --> $DIR/issue-7364.rs:6:15
+  --> $DIR/issue-7364.rs:4:15
    |
-LL | static boxed: Box<RefCell<isize>> = box RefCell::new(0);
+LL | static boxed: Box<RefCell<isize>> = Box::new(RefCell::new(0));
    |               ^^^^^^^^^^^^^^^^^^^ `RefCell<isize>` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `RefCell<isize>`
-   = note: required because of the requirements on the impl of `Sync` for `Unique<RefCell<isize>>`
+   = note: required for `Unique<RefCell<isize>>` to implement `Sync`
    = note: required because it appears within the type `Box<RefCell<isize>>`
    = note: shared static variables must have a type that implements `Sync`
 
diff --git a/src/test/ui/issues/issue-7673-cast-generically-implemented-trait.rs b/src/test/ui/issues/issue-7673-cast-generically-implemented-trait.rs
index 2961dc79f..c089c3308 100644
--- a/src/test/ui/issues/issue-7673-cast-generically-implemented-trait.rs
+++ b/src/test/ui/issues/issue-7673-cast-generically-implemented-trait.rs
@@ -8,8 +8,6 @@
 
 */
 
-#![feature(box_syntax)]
-
 pub fn main() {}
 
 trait A {
@@ -19,4 +17,4 @@ trait A {
 impl<T: 'static> A for T {}
 
 fn owned2<T: 'static>(a: Box<T>) { a as Box<dyn A>; }
-fn owned3<T: 'static>(a: Box<T>) { box a as Box<dyn A>; }
+fn owned3<T: 'static>(a: Box<T>) { Box::new(a) as Box<dyn A>; }
diff --git a/src/test/ui/issues/issue-86756.stderr b/src/test/ui/issues/issue-86756.stderr
index 399c940ca..b26c1834d 100644
--- a/src/test/ui/issues/issue-86756.stderr
+++ b/src/test/ui/issues/issue-86756.stderr
@@ -25,9 +25,8 @@ LL |     eq::<dyn, Foo>
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     eq::<dyn, Foo>
-LL +     eq::<dyn, dyn Foo>
-   |
+LL |     eq::<dyn, dyn Foo>
+   |               +++
 
 error[E0107]: missing generics for trait `Foo`
   --> $DIR/issue-86756.rs:5:15
diff --git a/src/test/ui/issues/issue-9129.rs b/src/test/ui/issues/issue-9129.rs
index 780a6419c..04110b3ae 100644
--- a/src/test/ui/issues/issue-9129.rs
+++ b/src/test/ui/issues/issue-9129.rs
@@ -4,8 +4,6 @@
 #![allow(non_snake_case)]
 // ignore-pretty unreported
 
-#![feature(box_syntax)]
-
 pub trait bomb { fn boom(&self, _: Ident); }
 pub struct S;
 impl bomb for S { fn boom(&self, _: Ident) { } }
@@ -29,6 +27,6 @@ pub fn light_fuse(fld: Box<dyn bomb>) {
 }
 
 pub fn main() {
-    let b = box S as Box<dyn bomb>;
+    let b = Box::new(S) as Box<dyn bomb>;
     light_fuse(b);
 }
diff --git a/src/test/ui/issues/issue-9382.rs b/src/test/ui/issues/issue-9382.rs
index dbb0fa524..65718343f 100644
--- a/src/test/ui/issues/issue-9382.rs
+++ b/src/test/ui/issues/issue-9382.rs
@@ -3,7 +3,6 @@
 
 // run-pass
 #![allow(dead_code)]
-#![feature(box_syntax)]
 
 // Tests for a previous bug that occurred due to an interaction
 // between struct field initialization and the auto-coercion
@@ -24,11 +23,11 @@ struct Thing2<'a> {
 pub fn main() {
     let _t1_fixed = Thing1 {
         baz: &[],
-        bar: box 32,
+        bar: Box::new(32),
     };
     Thing1 {
         baz: &Vec::new(),
-        bar: box 32,
+        bar: Box::new(32),
     };
     let _t2_fixed = Thing2 {
         baz: &[],
diff --git a/src/test/ui/issues/issue-99875.rs b/src/test/ui/issues/issue-99875.rs
new file mode 100644
index 000000000..cf73fd8d3
--- /dev/null
+++ b/src/test/ui/issues/issue-99875.rs
@@ -0,0 +1,16 @@
+struct Argument;
+struct Return;
+
+fn function(_: Argument) -> Return { todo!() }
+
+trait Trait {}
+impl Trait for fn(Argument) -> Return {}
+
+fn takes(_: impl Trait) {}
+
+fn main() {
+    takes(function);
+    //~^ ERROR the trait bound
+    takes(|_: Argument| -> Return { todo!() });
+    //~^ ERROR the trait bound
+}
diff --git a/src/test/ui/issues/issue-99875.stderr b/src/test/ui/issues/issue-99875.stderr
new file mode 100644
index 000000000..3ff8f12f1
--- /dev/null
+++ b/src/test/ui/issues/issue-99875.stderr
@@ -0,0 +1,33 @@
+error[E0277]: the trait bound `fn(Argument) -> Return {function}: Trait` is not satisfied
+  --> $DIR/issue-99875.rs:12:11
+   |
+LL |     takes(function);
+   |     ----- ^^^^^^^^ the trait `Trait` is not implemented for fn item `fn(Argument) -> Return {function}`
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `Trait` is implemented for fn pointer `fn(Argument) -> Return`
+note: required by a bound in `takes`
+  --> $DIR/issue-99875.rs:9:18
+   |
+LL | fn takes(_: impl Trait) {}
+   |                  ^^^^^ required by this bound in `takes`
+
+error[E0277]: the trait bound `[closure@$DIR/issue-99875.rs:14:11: 14:34]: Trait` is not satisfied
+  --> $DIR/issue-99875.rs:14:11
+   |
+LL |     takes(|_: Argument| -> Return { todo!() });
+   |     ----- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Trait` is not implemented for closure `[closure@$DIR/issue-99875.rs:14:11: 14:34]`
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `Trait` is implemented for fn pointer `fn(Argument) -> Return`
+note: required by a bound in `takes`
+  --> $DIR/issue-99875.rs:9:18
+   |
+LL | fn takes(_: impl Trait) {}
+   |                  ^^^^^ required by this bound in `takes`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.