Auto merge of #106588 - JohnTitor:rollup-4z80tjx, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #103104 (Stabilize `main_separator_str`)
 - #106410 (Suggest `mut self: &mut Self` for `?Sized` impls)
 - #106457 (Adjust comments about pre-push.sh hook)
 - #106546 (jsondoclint: Check local items in `paths` are also in `index`.)
 - #106557 (Add some UI tests and reword error-code docs)
 - #106562 (Clarify examples for `VecDeque::get/get_mut`)
 - #106580 (remove unreachable error code `E0313`)
 - #106581 (Do not emit wrong E0308 suggestion for closure mismatch)

Failed merges:

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

2 files changed, 9 insertions, 17 deletions

diff --git a/compiler/rustc_error_codes/src/error_codes.rs b/compiler/rustc_error_codes/src/error_codes.rs
index 3fba2cf5749..76d5da19399 100644
--- a/compiler/rustc_error_codes/src/error_codes.rs
+++ b/compiler/rustc_error_codes/src/error_codes.rs
@@ -579,8 +579,7 @@ E0791: include_str!("./error_codes/E0791.md"),
 //  E0300, // unexpanded macro
 //  E0304, // expected signed integer constant
 //  E0305, // expected constant
-    E0313, // lifetime of borrowed pointer outlives lifetime of captured
-           // variable
+//  E0313, // removed: found unreachable
 //  E0314, // closure outlives stack frame
 //  E0315, // cannot invoke closure outside of its lifetime
 //  E0319, // trait impls for defaulted traits allowed just for structs/enums
diff --git a/compiler/rustc_error_codes/src/error_codes/E0015.md b/compiler/rustc_error_codes/src/error_codes/E0015.md
index 021a0219d13..ac78f66adad 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0015.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0015.md
@@ -1,5 +1,4 @@
-A constant item was initialized with something that is not a constant
-expression.
+A non-`const` function was called in a `const` context.
 
 Erroneous code example:
 
@@ -8,26 +7,20 @@ fn create_some() -> Option<u8> {
     Some(1)
 }
 
-const FOO: Option<u8> = create_some(); // error!
+// error: cannot call non-const fn `create_some` in constants
+const FOO: Option<u8> = create_some();
 ```
 
-The only functions that can be called in static or constant expressions are
-`const` functions, and struct/enum constructors.
+All functions used in a `const` context (constant or static expression) must
+be marked `const`.
 
 To fix this error, you can declare `create_some` as a constant function:
 
 ```
-const fn create_some() -> Option<u8> { // declared as a const function
+// declared as a `const` function:
+const fn create_some() -> Option<u8> {
     Some(1)
 }
 
-const FOO: Option<u8> = create_some(); // ok!
-
-// These are also working:
-struct Bar {
-    x: u8,
-}
-
-const OTHER_FOO: Option<u8> = Some(1);
-const BAR: Bar = Bar {x: 1};
+const FOO: Option<u8> = create_some(); // no error!
 ```