From ae61c250cd6124d0ec5095acb3be64b633268ab3 Mon Sep 17 00:00:00 2001
From: Ezra Shaw <ezrasure@outlook.com>
Date: Sat, 7 Jan 2023 18:37:40 +1300
Subject: doc/test: add UI test and reword docs for `E0013` and `E0015`

---
 .../rustc_error_codes/src/error_codes/E0015.md     | 23 ++++++++--------------
 1 file changed, 8 insertions(+), 15 deletions(-)

(limited to 'compiler/rustc_error_codes/src')

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!
 ```
-- 
cgit 1.4.1-3-g733a5