Warn when Smex is loaded on incompatible Emacsen

Fixes #36 Thanks to Steve Purcell for suggesting this patch
nonsequitur · Jan 31, 2014 · ab59af5 · ab59af5 · purcell · Jan 31, 2014
1 parent 0fc84c0
commit ab59af5
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/smex.el b/smex.el
@@ -73,6 +73,12 @@ Set this to nil to disable fuzzy matching."
 (defvar smex-command-count 0)
 (defvar smex-custom-action nil)
 
+;; Check if Smex is supported
+(when (equal (cons 1 1)
+             (ignore-errors
+               (subr-arity (symbol-function 'execute-extended-command))))
+  (error "Your Emacs has a non-elisp version of `execute-extended-command', which is incompatible with Smex"))
+
 ;;--------------------------------------------------------------------------------
 ;; Smex Interface