Rollup merge of #118486 - RalfJung:add-feature, r=compiler-errors

generic_const_exprs: suggest to add the feature, not use it

Usually our missing feature messages look something like
```
  = help: add `#![feature(inline_const)]` to the crate attributes to enable
```
However `generic_const_exprs` used a different verb. That's inconsistent and it also means playground won't add that nice hyperlink to add the feature automatically. So let's use the same verb as everywhere else.

Author: TaKO8Ki

compiler/rustc_resolve/messages.ftl

@@ -200,7 +200,7 @@ resolve_param_in_non_trivial_anon_const =
     .label = cannot perform const operation using `{$name}`
 
 resolve_param_in_non_trivial_anon_const_help =
-    use `#![feature(generic_const_exprs)]` to allow generic const expressions
+    add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 resolve_param_in_ty_of_const_param =
     the type of const parameters must not depend on other generic parameters

tests/ui/associated-consts/associated-const-type-parameter-arrays.stderr

@@ -5,7 +5,7 @@ LL |     let _array: [u32; <A as Foo>::Y];
    |                        ^ cannot perform const operation using `A`
    |
    = note: type parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: aborting due to 1 previous error
 

tests/ui/associated-item/associated-item-duplicate-bounds.stderr

@@ -5,7 +5,7 @@ LL |     links: [u32; A::LINKS], // Shouldn't suggest bounds already there.
    |                  ^^^^^^^^ cannot perform const operation using `A`
    |
    = note: type parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: aborting due to 1 previous error
 

tests/ui/const-generics/const-arg-in-const-arg.min.stderr

@@ -5,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:16:23
@@ -14,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:18:23
@@ -23,7 +23,7 @@ LL |     let _: [u8; faz::<'a>(&())];
    |                       ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:20:23
@@ -32,7 +32,7 @@ LL |     let _: [u8; baz::<'a>(&())];
    |                       ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:21:23
@@ -41,7 +41,7 @@ LL |     let _: [u8; faz::<'b>(&())];
    |                       ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:23:23
@@ -50,7 +50,7 @@ LL |     let _: [u8; baz::<'b>(&())];
    |                       ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:26:23
@@ -59,7 +59,7 @@ 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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:28:23
@@ -68,7 +68,7 @@ LL |     let _ = [0; faz::<'a>(&())];
    |                       ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:30:23
@@ -77,7 +77,7 @@ LL |     let _ = [0; baz::<'a>(&())];
    |                       ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:31:23
@@ -86,7 +86,7 @@ LL |     let _ = [0; faz::<'b>(&())];
    |                       ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:33:23
@@ -95,7 +95,7 @@ LL |     let _ = [0; baz::<'b>(&())];
    |                       ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:34:24
@@ -104,7 +104,7 @@ LL |     let _: Foo<{ foo::<T>() }>;
    |                        ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:35:24
@@ -113,7 +113,7 @@ 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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:37:24
@@ -122,7 +122,7 @@ LL |     let _: Foo<{ faz::<'a>(&()) }>;
    |                        ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:39:24
@@ -131,7 +131,7 @@ LL |     let _: Foo<{ baz::<'a>(&()) }>;
    |                        ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:40:24
@@ -140,7 +140,7 @@ LL |     let _: Foo<{ faz::<'b>(&()) }>;
    |                        ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:42:24
@@ -149,7 +149,7 @@ LL |     let _: Foo<{ baz::<'b>(&()) }>;
    |                        ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:43:27
@@ -158,7 +158,7 @@ LL |     let _ = Foo::<{ foo::<T>() }>;
    |                           ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:44:27
@@ -167,7 +167,7 @@ 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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:46:27
@@ -176,7 +176,7 @@ LL |     let _ = Foo::<{ faz::<'a>(&()) }>;
    |                           ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:48:27
@@ -185,7 +185,7 @@ LL |     let _ = Foo::<{ baz::<'a>(&()) }>;
    |                           ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:49:27
@@ -194,7 +194,7 @@ LL |     let _ = Foo::<{ faz::<'b>(&()) }>;
    |                           ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/const-arg-in-const-arg.rs:51:27
@@ -203,7 +203,7 @@ LL |     let _ = Foo::<{ baz::<'b>(&()) }>;
    |                           ^^ cannot perform const operation using `'b`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error[E0747]: unresolved item provided when a constant was expected
   --> $DIR/const-arg-in-const-arg.rs:16:23

tests/ui/const-generics/const-argument-if-length.min.stderr

@@ -5,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` 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:15:12

tests/ui/const-generics/const-argument-non-static-lifetime.min.stderr

@@ -5,7 +5,7 @@ LL |         let _: &'a ();
    |                 ^^ cannot perform const operation using `'a`
    |
    = note: lifetime parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: aborting due to 1 previous error
 

tests/ui/const-generics/defaults/complex-generic-default-expr.min.stderr

@@ -5,7 +5,7 @@ LL | struct Foo<const N: usize, const M: usize = { N + 1 }>;
    |                                               ^ cannot perform const operation using `N`
    |
    = help: const parameters may only be used as standalone arguments, i.e. `N`
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/complex-generic-default-expr.rs:9:62
@@ -14,7 +14,7 @@ LL | struct Bar<T, const TYPE_SIZE: usize = { std::mem::size_of::<T>() }>(T);
    |                                                              ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: aborting due to 2 previous errors
 

tests/ui/const-generics/early/macro_rules-braces.stderr

@@ -27,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/macro_rules-braces.rs:36:19
@@ -36,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/macro_rules-braces.rs:41:20
@@ -45,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/macro_rules-braces.rs:46:19
@@ -54,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: aborting due to 6 previous errors
 

tests/ui/const-generics/generic_const_exprs/array-size-in-generic-struct-param.min.stderr

@@ -5,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/array-size-in-generic-struct-param.rs:23:15
@@ -14,7 +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(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` 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:21:21

tests/ui/const-generics/generic_const_exprs/dependence_lint.full.stderr

@@ -5,7 +5,7 @@ LL |     let _: [u8; size_of::<*mut T>()]; // error on stable, error with gce
    |                                ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 error: generic parameters may not be used in const operations
   --> $DIR/dependence_lint.rs:21:37
@@ -14,7 +14,7 @@ LL |     let _: [u8; if true { size_of::<T>() } else { 3 }]; // error on stable,
    |                                     ^ cannot perform const operation using `T`
    |
    = note: type parameters may not be used in const expressions
-   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions
+   = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions
 
 warning: cannot use constants which depend on generic parameters in types
   --> $DIR/dependence_lint.rs:10:9