Rollup merge of #72137 - GuillaumeGomez:cleanup-e0581, r=Dylan-DPC

Clean up E0581 explanation

r? @Dylan-DPC

1 files changed, 6 insertions, 3 deletions

diff --git a/src/librustc_error_codes/error_codes/E0581.md b/src/librustc_error_codes/error_codes/E0581.md
index 947ec255a9d..89f6e3269ec 100644
--- a/src/librustc_error_codes/error_codes/E0581.md
+++ b/src/librustc_error_codes/error_codes/E0581.md
@@ -1,4 +1,4 @@
-In a `fn` type, a lifetime appears only in the return type,
+In a `fn` type, a lifetime appears only in the return type
 and not in the arguments types.
 
 Erroneous code example:
@@ -10,8 +10,11 @@ fn main() {
 }
 ```
 
-To fix this issue, either use the lifetime in the arguments, or use
-`'static`. Example:
+The problem here is that the lifetime isn't contrained by any of the arguments,
+making it impossible to determine how long it's supposed to live.
+
+To fix this issue, either use the lifetime in the arguments, or use the
+`'static` lifetime. Example:
 
 ```
 fn main() {