Auto merge of #79377 - jonas-schievink:rollup-ye81i66, r=jonas-schievink

Rollup of 10 pull requests

Successful merges:

 - #76858 (Add exploit mitigations chapter to the rustc book)
 - #79310 (Make `fold_item_recur` non-nullable)
 - #79312 (Get rid of `doctree::Impl`)
 - #79321 (Accept '!' in intra-doc links)
 - #79346 (Allow using `-Z fewer-names=no` to retain value names)
 - #79351 (Fix typo in `keyword` docs for traits)
 - #79354 (BTreeMap: cut out the ceremony around BoxedNode)
 - #79358 (BTreeMap/BTreeSet: make public doc more consistent)
 - #79367 (Allow disabling TrapUnreachable via -Ztrap-unreachable=no)
 - #79374 (Add note to use nightly when using expr in const generics)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

57 files changed, 143 insertions, 62 deletions

diff --git a/src/test/codegen/fewer-names.rs b/src/test/codegen/fewer-names.rs
new file mode 100644
index 00000000000..53a926d49ef
--- /dev/null
+++ b/src/test/codegen/fewer-names.rs
@@ -0,0 +1,20 @@
+// no-system-llvm
+// compile-flags: -Coverflow-checks=no -O
+// revisions: YES NO
+// [YES]compile-flags: -Zfewer-names=yes
+// [NO] compile-flags: -Zfewer-names=no
+#![crate_type = "lib"]
+
+#[no_mangle]
+pub fn sum(x: u32, y: u32) -> u32 {
+// YES-LABEL: define i32 @sum(i32 %0, i32 %1)
+// YES-NEXT:    %3 = add i32 %1, %0
+// YES-NEXT:    ret i32 %3
+
+// NO-LABEL: define i32 @sum(i32 %x, i32 %y)
+// NO-NEXT:  start:
+// NO-NEXT:    %z = add i32 %y, %x
+// NO-NEXT:    ret i32 %z
+    let z = x + y;
+    z
+}
diff --git a/src/test/rustdoc-ui/intra-link-errors.stderr b/src/test/rustdoc-ui/intra-link-errors.stderr
index 31e7fc48afd..be98cac94ec 100644
--- a/src/test/rustdoc-ui/intra-link-errors.stderr
+++ b/src/test/rustdoc-ui/intra-link-errors.stderr
@@ -106,6 +106,15 @@ LL | /// [S!]
    |      this link resolves to the struct `S`, which is not in the macro namespace
    |      help: to link to the struct, prefix with `struct@`: `struct@S`
 
+error: unresolved link to `S::h`
+  --> $DIR/intra-link-errors.rs:78:6
+   |
+LL | /// [type@S::h]
+   |      ^^^^^^^^^
+   |      |
+   |      this link resolves to the associated function `h`, which is not in the type namespace
+   |      help: to link to the associated function, add parentheses: `S::h()`
+
 error: unresolved link to `T::g`
   --> $DIR/intra-link-errors.rs:86:6
    |
@@ -121,15 +130,6 @@ error: unresolved link to `T::h`
 LL | /// [T::h!]
    |      ^^^^^ the trait `T` has no macro named `h`
 
-error: unresolved link to `S::h`
-  --> $DIR/intra-link-errors.rs:78:6
-   |
-LL | /// [type@S::h]
-   |      ^^^^^^^^^
-   |      |
-   |      this link resolves to the associated function `h`, which is not in the type namespace
-   |      help: to link to the associated function, add parentheses: `S::h()`
-
 error: unresolved link to `m`
   --> $DIR/intra-link-errors.rs:98:6
    |
diff --git a/src/test/rustdoc/intra-doc-link-generic-params.rs b/src/test/rustdoc/intra-doc-link-generic-params.rs
index 7d7289437ff..1de6410f10c 100644
--- a/src/test/rustdoc/intra-doc-link-generic-params.rs
+++ b/src/test/rustdoc/intra-doc-link-generic-params.rs
@@ -15,8 +15,11 @@
 // @has foo/index.html '//a[@href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html"]' 'with the generic, Option<T>'
 
 //! We should also try linking to [`Result<T, E>`]; it has *two* generics!
+//! And [`Result<T, !>`] and [`Result<!, E>`].
 //!
 // @has foo/index.html '//a[@href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html"]' 'Result<T, E>'
+// @has foo/index.html '//a[@href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html"]' 'Result<T, !>'
+// @has foo/index.html '//a[@href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html"]' 'Result<!, E>'
 
 //! Now let's test a trickier case: [`Vec::<T>::new`], or you could write it
 //! [with parentheses as `Vec::<T>::new()`][Vec::<T>::new()].
diff --git a/src/test/ui/const-generics/array-size-in-generic-struct-param.min.stderr b/src/test/ui/const-generics/array-size-in-generic-struct-param.min.stderr
index cfaacf7a5be..73c9ea59c95 100644
--- a/src/test/ui/const-generics/array-size-in-generic-struct-param.min.stderr
+++ b/src/test/ui/const-generics/array-size-in-generic-struct-param.min.stderr
@@ -5,6 +5,7 @@ LL | struct ArithArrayLen<const N: usize>([u32; 0 + N]);
    |                                                ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/array-size-in-generic-struct-param.rs:20:15
@@ -13,6 +14,7 @@ LL |     arr: [u8; CFG.arr_size],
    |               ^^^ cannot perform const operation using `CFG`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `CFG`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: `Config` is forbidden as the type of a const generic parameter
   --> $DIR/array-size-in-generic-struct-param.rs:18:21
@@ -21,7 +23,7 @@ LL | struct B<const CFG: Config> {
    |                     ^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/const-generics/const-arg-in-const-arg.min.stderr b/src/test/ui/const-generics/const-arg-in-const-arg.min.stderr
index 7dfe250b78e..042fa9ad958 100644
--- a/src/test/ui/const-generics/const-arg-in-const-arg.min.stderr
+++ b/src/test/ui/const-generics/const-arg-in-const-arg.min.stderr
@@ -5,6 +5,7 @@ LL |     let _: [u8; foo::<T>()];
    |                       ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:15:23
@@ -13,6 +14,7 @@ LL |     let _: [u8; bar::<N>()];
    |                       ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:25:23
@@ -21,6 +23,7 @@ LL |     let _ = [0; bar::<N>()];
    |                       ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:30:24
@@ -29,6 +32,7 @@ LL |     let _: Foo<{ foo::<T>() }>;
    |                        ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:31:24
@@ -37,6 +41,7 @@ LL |     let _: Foo<{ bar::<N>() }>;
    |                        ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:36:27
@@ -45,6 +50,7 @@ LL |     let _ = Foo::<{ foo::<T>() }>;
    |                           ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:37:27
@@ -53,6 +59,7 @@ LL |     let _ = Foo::<{ bar::<N>() }>;
    |                           ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0658]: a non-static lifetime is not allowed in a `const`
   --> $DIR/const-arg-in-const-arg.rs:16:23
diff --git a/src/test/ui/const-generics/const-argument-if-length.min.stderr b/src/test/ui/const-generics/const-argument-if-length.min.stderr
index bce701ade86..8a1074392a5 100644
--- a/src/test/ui/const-generics/const-argument-if-length.min.stderr
+++ b/src/test/ui/const-generics/const-argument-if-length.min.stderr
@@ -5,6 +5,7 @@ LL |     pad: [u8; is_zst::<T>()],
    |                        ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
   --> $DIR/const-argument-if-length.rs:17:12
diff --git a/src/test/ui/const-generics/const-param-before-other-params.min.stderr b/src/test/ui/const-generics/const-param-before-other-params.min.stderr
index c7e6d1be421..354c6d0615f 100644
--- a/src/test/ui/const-generics/const-param-before-other-params.min.stderr
+++ b/src/test/ui/const-generics/const-param-before-other-params.min.stderr
@@ -17,7 +17,7 @@ LL | fn bar<const X: (), 'a>(_: &'a ()) {
    |                 ^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `()` is forbidden as the type of a const generic parameter
   --> $DIR/const-param-before-other-params.rs:11:17
@@ -26,7 +26,7 @@ LL | fn foo<const X: (), T>(_: &T) {}
    |                 ^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/const-generics/const-param-elided-lifetime.min.stderr b/src/test/ui/const-generics/const-param-elided-lifetime.min.stderr
index 81dbaee0ec5..ed30182690a 100644
--- a/src/test/ui/const-generics/const-param-elided-lifetime.min.stderr
+++ b/src/test/ui/const-generics/const-param-elided-lifetime.min.stderr
@@ -35,7 +35,7 @@ LL | struct A<const N: &u8>;
    |                   ^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static u8` is forbidden as the type of a const generic parameter
   --> $DIR/const-param-elided-lifetime.rs:16:15
@@ -44,7 +44,7 @@ LL | impl<const N: &u8> A<N> {
    |               ^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static u8` is forbidden as the type of a const generic parameter
   --> $DIR/const-param-elided-lifetime.rs:24:15
@@ -53,7 +53,7 @@ LL | impl<const N: &u8> B for A<N> {}
    |               ^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static u8` is forbidden as the type of a const generic parameter
   --> $DIR/const-param-elided-lifetime.rs:28:17
@@ -62,7 +62,7 @@ LL | fn bar<const N: &u8>() {}
    |                 ^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static u8` is forbidden as the type of a const generic parameter
   --> $DIR/const-param-elided-lifetime.rs:19:21
@@ -71,7 +71,7 @@ LL |     fn foo<const M: &u8>(&self) {}
    |                     ^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 10 previous errors
 
diff --git a/src/test/ui/const-generics/const-param-type-depends-on-const-param.min.stderr b/src/test/ui/const-generics/const-param-type-depends-on-const-param.min.stderr
index b00a1607876..6b7a218ada5 100644
--- a/src/test/ui/const-generics/const-param-type-depends-on-const-param.min.stderr
+++ b/src/test/ui/const-generics/const-param-type-depends-on-const-param.min.stderr
@@ -17,7 +17,7 @@ LL | pub struct Dependent<const N: usize, const X: [u8; N]>([(); N]);
    |                                               ^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `[u8; _]` is forbidden as the type of a const generic parameter
   --> $DIR/const-param-type-depends-on-const-param.rs:16:35
@@ -26,7 +26,7 @@ LL | pub struct SelfDependent<const N: [u8; N]>;
    |                                   ^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.min.stderr b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.min.stderr
index 359c2d2a22f..573bc66b7c7 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.min.stderr
+++ b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.min.stderr
@@ -5,6 +5,7 @@ LL | type Arr<const N: usize> = [u8; N - 1];
    |                                 ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/simple.min.stderr b/src/test/ui/const-generics/const_evaluatable_checked/simple.min.stderr
index 46485262cc4..d476a7eb645 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/simple.min.stderr
+++ b/src/test/ui/const-generics/const_evaluatable_checked/simple.min.stderr
@@ -5,6 +5,7 @@ LL | fn test<const N: usize>() -> [u8; N - 1] where [u8; N - 1]: Default {
    |                                                     ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/simple.rs:8:35
@@ -13,6 +14,7 @@ LL | fn test<const N: usize>() -> [u8; N - 1] where [u8; N - 1]: Default {
    |                                   ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.min.stderr b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.min.stderr
index 981d993f589..bd81e0bc5a8 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.min.stderr
+++ b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.min.stderr
@@ -5,6 +5,7 @@ LL | type Arr<const N: usize> = [u8; N - 1];
    |                                 ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/different_byref.min.stderr b/src/test/ui/const-generics/different_byref.min.stderr
index 050b28abe50..e5b393ffe99 100644
--- a/src/test/ui/const-generics/different_byref.min.stderr
+++ b/src/test/ui/const-generics/different_byref.min.stderr
@@ -5,7 +5,7 @@ LL | struct Const<const V: [usize; 1]> {}
    |                       ^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/forbid-non-structural_match-types.min.stderr b/src/test/ui/const-generics/forbid-non-structural_match-types.min.stderr
index 40d8f44cafc..014200178b9 100644
--- a/src/test/ui/const-generics/forbid-non-structural_match-types.min.stderr
+++ b/src/test/ui/const-generics/forbid-non-structural_match-types.min.stderr
@@ -5,7 +5,7 @@ LL | struct B<const X: A>; // ok
    |                   ^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `C` is forbidden as the type of a const generic parameter
   --> $DIR/forbid-non-structural_match-types.rs:15:19
@@ -14,7 +14,7 @@ LL | struct D<const X: C>;
    |                   ^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error[E0741]: `C` must be annotated with `#[derive(PartialEq, Eq)]` to be used as the type of a const parameter
   --> $DIR/forbid-non-structural_match-types.rs:15:19
diff --git a/src/test/ui/const-generics/generic-function-call-in-array-length.min.stderr b/src/test/ui/const-generics/generic-function-call-in-array-length.min.stderr
index 84449018e46..526f98fe8cd 100644
--- a/src/test/ui/const-generics/generic-function-call-in-array-length.min.stderr
+++ b/src/test/ui/const-generics/generic-function-call-in-array-length.min.stderr
@@ -5,6 +5,7 @@ LL | fn bar<const N: usize>() -> [u32; foo(N)] {
    |                                       ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/generic-function-call-in-array-length.rs:12:13
@@ -13,6 +14,7 @@ LL |     [0; foo(N)]
    |             ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/generic-sum-in-array-length.min.stderr b/src/test/ui/const-generics/generic-sum-in-array-length.min.stderr
index d3f7143327e..e531b612b56 100644
--- a/src/test/ui/const-generics/generic-sum-in-array-length.min.stderr
+++ b/src/test/ui/const-generics/generic-sum-in-array-length.min.stderr
@@ -5,6 +5,7 @@ LL | fn foo<const A: usize, const B: usize>(bar: [usize; A + B]) {}
    |                                                     ^ cannot perform const operation using `A`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `A`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/generic-sum-in-array-length.rs:7:57
@@ -13,6 +14,7 @@ LL | fn foo<const A: usize, const B: usize>(bar: [usize; A + B]) {}
    |                                                         ^ cannot perform const operation using `B`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `B`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/intrinsics-type_name-as-const-argument.min.stderr b/src/test/ui/const-generics/intrinsics-type_name-as-const-argument.min.stderr
index 20a8d9fdaab..02467df193c 100644
--- a/src/test/ui/const-generics/intrinsics-type_name-as-const-argument.min.stderr
+++ b/src/test/ui/const-generics/intrinsics-type_name-as-const-argument.min.stderr
@@ -5,6 +5,7 @@ LL |     T: Trait<{std::intrinsics::type_name::<T>()}>
    |                                            ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: `&'static str` is forbidden as the type of a const generic parameter
   --> $DIR/intrinsics-type_name-as-const-argument.rs:10:22
@@ -13,7 +14,7 @@ LL | trait Trait<const S: &'static str> {}
    |                      ^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/issue-61522-array-len-succ.min.stderr b/src/test/ui/const-generics/issue-61522-array-len-succ.min.stderr
index 526807f0a24..2eaef95c232 100644
--- a/src/test/ui/const-generics/issue-61522-array-len-succ.min.stderr
+++ b/src/test/ui/const-generics/issue-61522-array-len-succ.min.stderr
@@ -5,6 +5,7 @@ LL | pub struct MyArray<const COUNT: usize>([u8; COUNT + 1]);
    |                                             ^^^^^ cannot perform const operation using `COUNT`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `COUNT`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-61522-array-len-succ.rs:12:30
@@ -13,6 +14,7 @@ LL |     fn inner(&self) -> &[u8; COUNT + 1] {
    |                              ^^^^^ cannot perform const operation using `COUNT`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `COUNT`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/issue-66596-impl-trait-for-str-const-arg.min.stderr b/src/test/ui/const-generics/issue-66596-impl-trait-for-str-const-arg.min.stderr
index 786ded3c2fe..1c2e7e069a1 100644
--- a/src/test/ui/const-generics/issue-66596-impl-trait-for-str-const-arg.min.stderr
+++ b/src/test/ui/const-generics/issue-66596-impl-trait-for-str-const-arg.min.stderr
@@ -5,7 +5,7 @@ LL | trait Trait<const NAME: &'static str> {
    |                         ^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issue-67375.min.stderr b/src/test/ui/const-generics/issue-67375.min.stderr
index 3c344edbf1d..da96b5374a5 100644
--- a/src/test/ui/const-generics/issue-67375.min.stderr
+++ b/src/test/ui/const-generics/issue-67375.min.stderr
@@ -5,6 +5,7 @@ LL |     inner: [(); { [|_: &T| {}; 0].len() }],
    |                         ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0392]: parameter `T` is never used
   --> $DIR/issue-67375.rs:7:12
diff --git a/src/test/ui/const-generics/issue-67945-1.min.stderr b/src/test/ui/const-generics/issue-67945-1.min.stderr
index 804236c30bd..8fea130baa5 100644
--- a/src/test/ui/const-generics/issue-67945-1.min.stderr
+++ b/src/test/ui/const-generics/issue-67945-1.min.stderr
@@ -5,6 +5,7 @@ LL |         let x: S = MaybeUninit::uninit();
    |                ^ cannot perform const operation using `S`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-67945-1.rs:17:45
@@ -13,6 +14,7 @@ LL |         let b = &*(&x as *const _ as *const S);
    |                                             ^ cannot perform const operation using `S`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0392]: parameter `S` is never used
   --> $DIR/issue-67945-1.rs:11:12
diff --git a/src/test/ui/const-generics/issue-67945-2.min.stderr b/src/test/ui/const-generics/issue-67945-2.min.stderr
index 2de942c1220..50633772b75 100644
--- a/src/test/ui/const-generics/issue-67945-2.min.stderr
+++ b/src/test/ui/const-generics/issue-67945-2.min.stderr
@@ -5,6 +5,7 @@ LL |         let x: S = MaybeUninit::uninit();
    |                ^ cannot perform const operation using `S`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-67945-2.rs:15:45
@@ -13,6 +14,7 @@ LL |         let b = &*(&x as *const _ as *const S);
    |                                             ^ cannot perform const operation using `S`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0392]: parameter `S` is never used
   --> $DIR/issue-67945-2.rs:9:12
diff --git a/src/test/ui/const-generics/issues/issue-61747.min.stderr b/src/test/ui/const-generics/issues/issue-61747.min.stderr
index b176f9d1c75..1de9e71b6eb 100644
--- a/src/test/ui/const-generics/issues/issue-61747.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-61747.min.stderr
@@ -5,6 +5,7 @@ LL |     fn successor() -> Const<{C + 1}> {
    |                              ^ cannot perform const operation using `C`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `C`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-61935.min.stderr b/src/test/ui/const-generics/issues/issue-61935.min.stderr
index 9e31466259f..b1d92056a54 100644
--- a/src/test/ui/const-generics/issues/issue-61935.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-61935.min.stderr
@@ -5,6 +5,7 @@ LL |         Self:FooImpl<{N==0}>
    |                       ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-62220.min.stderr b/src/test/ui/const-generics/issues/issue-62220.min.stderr
index 3bd127ee74a..b338cdb87e1 100644
--- a/src/test/ui/const-generics/issues/issue-62220.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-62220.min.stderr
@@ -5,6 +5,7 @@ LL | pub type TruncatedVector<T, const N: usize> = Vector<T, { N - 1 }>;
    |                                                           ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-62456.min.stderr b/src/test/ui/const-generics/issues/issue-62456.min.stderr
index c73f62a4a07..a4b501a7bb1 100644
--- a/src/test/ui/const-generics/issues/issue-62456.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-62456.min.stderr
@@ -5,6 +5,7 @@ LL |     let _ = [0u64; N + 1];
    |                    ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-62579-no-match.min.stderr b/src/test/ui/const-generics/issues/issue-62579-no-match.min.stderr
index 6903b20fad6..5117e20d626 100644
--- a/src/test/ui/const-generics/issues/issue-62579-no-match.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-62579-no-match.min.stderr
@@ -5,7 +5,7 @@ LL | fn foo<const T: NoMatch>() -> bool {
    |                 ^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-62878.min.stderr b/src/test/ui/const-generics/issues/issue-62878.min.stderr
index 34edd09b515..9f95e5d8862 100644
--- a/src/test/ui/const-generics/issues/issue-62878.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-62878.min.stderr
@@ -11,7 +11,7 @@ LL | fn foo<const N: usize, const A: [u8; N]>() {}
    |                                 ^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/issues/issue-63322-forbid-dyn.min.stderr b/src/test/ui/const-generics/issues/issue-63322-forbid-dyn.min.stderr
index e6d9fb7a246..5dbfdc6d652 100644
--- a/src/test/ui/const-generics/issues/issue-63322-forbid-dyn.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-63322-forbid-dyn.min.stderr
@@ -5,7 +5,7 @@ LL | fn test<const T: &'static dyn A>() {
    |                  ^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error[E0741]: `&'static (dyn A + 'static)` must be annotated with `#[derive(PartialEq, Eq)]` to be used as the type of a const parameter
   --> $DIR/issue-63322-forbid-dyn.rs:10:18
diff --git a/src/test/ui/const-generics/issues/issue-64494.min.stderr b/src/test/ui/const-generics/issues/issue-64494.min.stderr
index 8b02fd108bd..681166b1d2b 100644
--- a/src/test/ui/const-generics/issues/issue-64494.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-64494.min.stderr
@@ -5,6 +5,7 @@ LL | impl<T: Foo> MyTrait for T where Is<{T::VAL == 5}>: True {}
    |                                      ^^^^^^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-64494.rs:19:38
@@ -13,6 +14,7 @@ LL | impl<T: Foo> MyTrait for T where Is<{T::VAL == 6}>: True {}
    |                                      ^^^^^^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0119]: conflicting implementations of trait `MyTrait`:
   --> $DIR/issue-64494.rs:19:1
diff --git a/src/test/ui/const-generics/issues/issue-66205.min.stderr b/src/test/ui/const-generics/issues/issue-66205.min.stderr
index 282f72be6da..ecd96ac37e4 100644
--- a/src/test/ui/const-generics/issues/issue-66205.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-66205.min.stderr
@@ -5,6 +5,7 @@ LL |     fact::<{ N - 1 }>();
    |              ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-68366.min.stderr b/src/test/ui/const-generics/issues/issue-68366.min.stderr
index b900a0d096a..acaf4a33ee0 100644
--- a/src/test/ui/const-generics/issues/issue-68366.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-68366.min.stderr
@@ -5,6 +5,7 @@ LL | impl <const N: usize> Collatz<{Some(N)}> {}
    |                                     ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0207]: the const parameter `N` is not constrained by the impl trait, self type, or predicates
   --> $DIR/issue-68366.rs:12:13
diff --git a/src/test/ui/const-generics/issues/issue-68615-adt.min.stderr b/src/test/ui/const-generics/issues/issue-68615-adt.min.stderr
index 81c8f4392c7..59653114a6b 100644
--- a/src/test/ui/const-generics/issues/issue-68615-adt.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-68615-adt.min.stderr
@@ -5,7 +5,7 @@ LL | struct Const<const V: [usize; 0]> {}
    |                       ^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-68615-array.min.stderr b/src/test/ui/const-generics/issues/issue-68615-array.min.stderr
index 8f55a92fce9..1ee881b96ec 100644
--- a/src/test/ui/const-generics/issues/issue-68615-array.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-68615-array.min.stderr
@@ -5,7 +5,7 @@ LL | struct Foo<const V: [usize; 0] > {}
    |                     ^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-68977.min.stderr b/src/test/ui/const-generics/issues/issue-68977.min.stderr
index 7828d859394..ea91df1e0bf 100644
--- a/src/test/ui/const-generics/issues/issue-68977.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-68977.min.stderr
@@ -5,6 +5,7 @@ LL |     PhantomU8<{(INT_BITS + FRAC_BITS + 7) / 8}>;
    |                 ^^^^^^^^ cannot perform const operation using `INT_BITS`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `INT_BITS`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-68977.rs:29:28
@@ -13,6 +14,7 @@ LL |     PhantomU8<{(INT_BITS + FRAC_BITS + 7) / 8}>;
    |                            ^^^^^^^^^ cannot perform const operation using `FRAC_BITS`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `FRAC_BITS`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/issues/issue-71169.min.stderr b/src/test/ui/const-generics/issues/issue-71169.min.stderr
index 79d63443351..9b0a2946ca6 100644
--- a/src/test/ui/const-generics/issues/issue-71169.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-71169.min.stderr
@@ -11,7 +11,7 @@ LL | fn foo<const LEN: usize, const DATA: [u8; LEN]>() {}
    |                                      ^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/issues/issue-72787.min.stderr b/src/test/ui/const-generics/issues/issue-72787.min.stderr
index d960d9513b7..27bbc28011f 100644
--- a/src/test/ui/const-generics/issues/issue-72787.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-72787.min.stderr
@@ -5,6 +5,7 @@ LL |     Condition<{ LHS <= RHS }>: True
    |                 ^^^ cannot perform const operation using `LHS`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `LHS`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-72787.rs:11:24
@@ -13,6 +14,7 @@ LL |     Condition<{ LHS <= RHS }>: True
    |                        ^^^ cannot perform const operation using `RHS`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `RHS`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-72787.rs:26:25
@@ -21,6 +23,7 @@ LL |     IsLessOrEqual<{ 8 - I }, { 8 - J }>: True,
    |                         ^ cannot perform const operation using `I`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `I`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-72787.rs:26:36
@@ -29,6 +32,7 @@ LL |     IsLessOrEqual<{ 8 - I }, { 8 - J }>: True,
    |                                    ^ cannot perform const operation using `J`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `J`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error[E0283]: type annotations needed
   --> $DIR/issue-72787.rs:22:26
diff --git a/src/test/ui/const-generics/issues/issue-72819-generic-in-const-eval.min.stderr b/src/test/ui/const-generics/issues/issue-72819-generic-in-const-eval.min.stderr
index 9fec3eb946d..2394b23d799 100644
--- a/src/test/ui/const-generics/issues/issue-72819-generic-in-const-eval.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-72819-generic-in-const-eval.min.stderr
@@ -5,6 +5,7 @@ LL | where Assert::<{N < usize::max_value() / 2}>: IsTrue,
    |                 ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-73491.min.stderr b/src/test/ui/const-generics/issues/issue-73491.min.stderr
index 5bf3671d38b..3ff0563acc7 100644
--- a/src/test/ui/const-generics/issues/issue-73491.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-73491.min.stderr
@@ -5,7 +5,7 @@ LL | fn hoge<const IN: [u32; LEN]>() {}
    |                   ^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-74101.min.stderr b/src/test/ui/const-generics/issues/issue-74101.min.stderr
index 8062faefbe6..1351246667e 100644
--- a/src/test/ui/const-generics/issues/issue-74101.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-74101.min.stderr
@@ -5,7 +5,7 @@ LL | fn test<const N: [u8; 1 + 2]>() {}
    |                  ^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `[u8; _]` is forbidden as the type of a const generic parameter
   --> $DIR/issue-74101.rs:10:21
@@ -14,7 +14,7 @@ LL | struct Foo<const N: [u8; 1 + 2]>;
    |                     ^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/issues/issue-74255.min.stderr b/src/test/ui/const-generics/issues/issue-74255.min.stderr
index 86937d715c9..e3e8502ae63 100644
--- a/src/test/ui/const-generics/issues/issue-74255.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-74255.min.stderr
@@ -5,7 +5,7 @@ LL |     fn ice_struct_fn<const I: IceEnum>() {}
    |                               ^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-74950.min.stderr b/src/test/ui/const-generics/issues/issue-74950.min.stderr
index f093e6651bc..12947a2ab37 100644
--- a/src/test/ui/const-generics/issues/issue-74950.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-74950.min.stderr
@@ -5,7 +5,7 @@ LL | struct Outer<const I: Inner>;
    |                       ^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `Inner` is forbidden as the type of a const generic parameter
   --> $DIR/issue-74950.rs:18:23
@@ -14,7 +14,7 @@ LL | struct Outer<const I: Inner>;
    |                       ^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `Inner` is forbidden as the type of a const generic parameter
   --> $DIR/issue-74950.rs:18:23
@@ -23,7 +23,7 @@ LL | struct Outer<const I: Inner>;
    |                       ^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `Inner` is forbidden as the type of a const generic parameter
   --> $DIR/issue-74950.rs:18:23
@@ -32,7 +32,7 @@ LL | struct Outer<const I: Inner>;
    |                       ^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `Inner` is forbidden as the type of a const generic parameter
   --> $DIR/issue-74950.rs:18:23
@@ -41,7 +41,7 @@ LL | struct Outer<const I: Inner>;
    |                       ^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 5 previous errors
 
diff --git a/src/test/ui/const-generics/issues/issue-75047.min.stderr b/src/test/ui/const-generics/issues/issue-75047.min.stderr
index edc54b082db..b87bb18a5a6 100644
--- a/src/test/ui/const-generics/issues/issue-75047.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-75047.min.stderr
@@ -5,7 +5,7 @@ LL | struct Foo<const N: [u8; Bar::<u32>::value()]>;
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.min.stderr b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.min.stderr
index c10db84ea6e..551b8e43e1d 100644
--- a/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.min.stderr
@@ -5,6 +5,7 @@ LL | fn ty_param<T>() -> [u8; std::mem::size_of::<T>()] {
    |                                              ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/issue-76701-ty-param-in-const.rs:12:42
@@ -13,6 +14,7 @@ LL | fn const_param<const N: usize>() -> [u8; N + 1] {
    |                                          ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/macro_rules-braces.min.stderr b/src/test/ui/const-generics/macro_rules-braces.min.stderr
index c6425edc10f..c400e2c814d 100644
--- a/src/test/ui/const-generics/macro_rules-braces.min.stderr
+++ b/src/test/ui/const-generics/macro_rules-braces.min.stderr
@@ -27,6 +27,7 @@ LL |     let _: foo!({{ N }});
    |                    ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/macro_rules-braces.rs:41:19
@@ -35,6 +36,7 @@ LL |     let _: bar!({ N });
    |                   ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/macro_rules-braces.rs:46:20
@@ -43,6 +45,7 @@ LL |     let _: baz!({{ N }});
    |                    ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/macro_rules-braces.rs:51:19
@@ -51,6 +54,7 @@ LL |     let _: biz!({ N });
    |                   ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/const-generics/min_const_generics/complex-expression.stderr b/src/test/ui/const-generics/min_const_generics/complex-expression.stderr
index a8de987e167..2ea66279d46 100644
--- a/src/test/ui/const-generics/min_const_generics/complex-expression.stderr
+++ b/src/test/ui/const-generics/min_const_generics/complex-expression.stderr
@@ -5,6 +5,7 @@ LL | struct Break0<const N: usize>([u8; { N + 1 }]);
    |                                      ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/complex-expression.rs:14:40
@@ -13,6 +14,7 @@ LL | struct Break1<const N: usize>([u8; { { N } }]);
    |                                        ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/complex-expression.rs:18:17
@@ -21,6 +23,7 @@ LL |     let _: [u8; N + 1];
    |                 ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/complex-expression.rs:23:17
@@ -29,6 +32,7 @@ LL |     let _ = [0; N + 1];
    |                 ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/complex-expression.rs:27:45
@@ -37,6 +41,7 @@ LL | struct BreakTy0<T>(T, [u8; { size_of::<*mut T>() }]);
    |                                             ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/complex-expression.rs:30:47
@@ -45,6 +50,7 @@ LL | struct BreakTy1<T>(T, [u8; { { size_of::<*mut T>() } }]);
    |                                               ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/complex-expression.rs:34:32
@@ -53,6 +59,7 @@ LL |     let _: [u8; size_of::<*mut T>() + 1];
    |                                ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 warning: cannot use constants which depend on generic parameters in types
   --> $DIR/complex-expression.rs:39:17
diff --git a/src/test/ui/const-generics/min_const_generics/complex-types.stderr b/src/test/ui/const-generics/min_const_generics/complex-types.stderr
index 52ed3c1c6ee..5d473f1f876 100644
--- a/src/test/ui/const-generics/min_const_generics/complex-types.stderr
+++ b/src/test/ui/const-generics/min_const_generics/complex-types.stderr
@@ -5,7 +5,7 @@ LL | struct Foo<const N: [u8; 0]>;
    |                     ^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `()` is forbidden as the type of a const generic parameter
   --> $DIR/complex-types.rs:7:21
@@ -14,7 +14,7 @@ LL | struct Bar<const N: ()>;
    |                     ^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `No` is forbidden as the type of a const generic parameter
   --> $DIR/complex-types.rs:12:21
@@ -23,7 +23,7 @@ LL | struct Fez<const N: No>;
    |                     ^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static u8` is forbidden as the type of a const generic parameter
   --> $DIR/complex-types.rs:15:21
@@ -32,7 +32,7 @@ LL | struct Faz<const N: &'static u8>;
    |                     ^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `!` is forbidden as the type of a const generic parameter
   --> $DIR/complex-types.rs:18:21
@@ -41,7 +41,7 @@ LL | struct Fiz<const N: !>;
    |                     ^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `()` is forbidden as the type of a const generic parameter
   --> $DIR/complex-types.rs:21:19
@@ -50,7 +50,7 @@ LL | enum Goo<const N: ()> { A, B }
    |                   ^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `()` is forbidden as the type of a const generic parameter
   --> $DIR/complex-types.rs:24:20
@@ -59,7 +59,7 @@ LL | union Boo<const N: ()> { a: () }
    |                    ^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 7 previous errors
 
diff --git a/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr b/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr
index 64da5e07df2..40c73f0b951 100644
--- a/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr
+++ b/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr
@@ -5,6 +5,7 @@ LL |     fn t1() -> [u8; std::mem::size_of::<Self>()];
    |                                         ^^^^ cannot perform const operation using `Self`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic `Self` types are currently not permitted in anonymous constants
   --> $DIR/self-ty-in-const-1.rs:14:41
diff --git a/src/test/ui/const-generics/min_const_generics/static-reference-array-const-param.stderr b/src/test/ui/const-generics/min_const_generics/static-reference-array-const-param.stderr
index cc32d8a67fe..6c39f6b4c1d 100644
--- a/src/test/ui/const-generics/min_const_generics/static-reference-array-const-param.stderr
+++ b/src/test/ui/const-generics/min_const_generics/static-reference-array-const-param.stderr
@@ -5,7 +5,7 @@ LL | fn a<const X: &'static [u32]>() {}
    |               ^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/min_const_generics/transmute-const-param-static-reference.stderr b/src/test/ui/const-generics/min_const_generics/transmute-const-param-static-reference.stderr
index 063120ad074..6b90329b72c 100644
--- a/src/test/ui/const-generics/min_const_generics/transmute-const-param-static-reference.stderr
+++ b/src/test/ui/const-generics/min_const_generics/transmute-const-param-static-reference.stderr
@@ -5,7 +5,7 @@ LL | struct Const<const P: &'static ()>;
    |                       ^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/nested-type.min.stderr b/src/test/ui/const-generics/nested-type.min.stderr
index 4f76ec6e02b..369e387508e 100644
--- a/src/test/ui/const-generics/nested-type.min.stderr
+++ b/src/test/ui/const-generics/nested-type.min.stderr
@@ -12,7 +12,7 @@ LL | | }]>;
    | |__^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
   --> $DIR/nested-type.rs:16:5
diff --git a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr
index 39aa8087cec..9e0837a0a62 100644
--- a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr
+++ b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr
@@ -13,6 +13,7 @@ LL | struct Foo<T, U = [u8; std::mem::size_of::<T>()]>(T, U);
    |                                            ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: constant values inside of type parameter defaults must not depend on generic parameters
   --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:12:21
diff --git a/src/test/ui/const-generics/slice-const-param-mismatch.min.stderr b/src/test/ui/const-generics/slice-const-param-mismatch.min.stderr
index 1f711bef4aa..46997fed770 100644
--- a/src/test/ui/const-generics/slice-const-param-mismatch.min.stderr
+++ b/src/test/ui/const-generics/slice-const-param-mismatch.min.stderr
@@ -5,7 +5,7 @@ LL | struct ConstString<const T: &'static str>;
    |                             ^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static [u8]` is forbidden as the type of a const generic parameter
   --> $DIR/slice-const-param-mismatch.rs:10:28
@@ -14,7 +14,7 @@ LL | struct ConstBytes<const T: &'static [u8]>;
    |                            ^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/slice-const-param.min.stderr b/src/test/ui/const-generics/slice-const-param.min.stderr
index 2a49619e661..7a9f65233e7 100644
--- a/src/test/ui/const-generics/slice-const-param.min.stderr
+++ b/src/test/ui/const-generics/slice-const-param.min.stderr
@@ -5,7 +5,7 @@ LL | pub fn function_with_str<const STRING: &'static str>() -> &'static str {
    |                                        ^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static [u8]` is forbidden as the type of a const generic parameter
   --> $DIR/slice-const-param.rs:13:41
@@ -14,7 +14,7 @@ LL | pub fn function_with_bytes<const BYTES: &'static [u8]>() -> &'static [u8] {
    |                                         ^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/std/const-generics-range.min.stderr b/src/test/ui/const-generics/std/const-generics-range.min.stderr
index 97be6ee6445..9274ccd2b92 100644
--- a/src/test/ui/const-generics/std/const-generics-range.min.stderr
+++ b/src/test/ui/const-generics/std/const-generics-range.min.stderr
@@ -5,7 +5,7 @@ LL | struct _Range<const R: std::ops::Range<usize>>;
    |                        ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `RangeFrom<usize>` is forbidden as the type of a const generic parameter
   --> $DIR/const-generics-range.rs:13:28
@@ -14,7 +14,7 @@ LL | struct _RangeFrom<const R: std::ops::RangeFrom<usize>>;
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `RangeFull` is forbidden as the type of a const generic parameter
   --> $DIR/const-generics-range.rs:18:28
@@ -23,7 +23,7 @@ LL | struct _RangeFull<const R: std::ops::RangeFull>;
    |                            ^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `RangeInclusive<usize>` is forbidden as the type of a const generic parameter
   --> $DIR/const-generics-range.rs:24:33
@@ -32,7 +32,7 @@ LL | struct _RangeInclusive<const R: std::ops::RangeInclusive<usize>>;
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `RangeTo<usize>` is forbidden as the type of a const generic parameter
   --> $DIR/const-generics-range.rs:29:26
@@ -41,7 +41,7 @@ LL | struct _RangeTo<const R: std::ops::RangeTo<usize>>;
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `RangeToInclusive<usize>` is forbidden as the type of a const generic parameter
   --> $DIR/const-generics-range.rs:34:35
@@ -50,7 +50,7 @@ LL | struct _RangeToInclusive<const R: std::ops::RangeToInclusive<usize>>;
    |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/const-generics/type-dependent/issue-71348.min.stderr b/src/test/ui/const-generics/type-dependent/issue-71348.min.stderr
index 8656239605d..8f240f0d930 100644
--- a/src/test/ui/const-generics/type-dependent/issue-71348.min.stderr
+++ b/src/test/ui/const-generics/type-dependent/issue-71348.min.stderr
@@ -5,7 +5,7 @@ LL | trait Get<'a, const N: &'static str> {
    |                        ^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: `&'static str` is forbidden as the type of a const generic parameter
   --> $DIR/issue-71348.rs:19:25
@@ -14,7 +14,7 @@ LL |     fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<N>>::Ta
    |                         ^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = note: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#[feature(const_generics)]`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/wf-misc.min.stderr b/src/test/ui/const-generics/wf-misc.min.stderr
index 935f12dd2c3..99142cb6ce7 100644
--- a/src/test/ui/const-generics/wf-misc.min.stderr
+++ b/src/test/ui/const-generics/wf-misc.min.stderr
@@ -5,6 +5,7 @@ LL |     let _: [u8; N + 1];
    |                 ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/wf-misc.rs:17:21
@@ -13,6 +14,7 @@ LL |     let _: Const::<{N + 1}>;
    |                     ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
+   = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors