* lisp/progmodes/cc-{defs,engine,langs,vars}.el: Comment the use of "a\\`"

lisp/progmodes/cc-langs.el

@@ -1280,7 +1280,7 @@ operators."
 	   (c--set-difference (c-lang-const c-assignment-operators)
 			      '("=")
 			      :test 'string-equal)))
-      "a\\`"))
+      "a\\`"))				; Doesn't match anything.
 (c-lang-defvar c-assignment-op-regexp
   (c-lang-const c-assignment-op-regexp))
 
@@ -1503,7 +1503,7 @@ properly."
   ;; language)
   t (if (c-lang-const c-block-comment-ender)
 	(regexp-quote (c-lang-const c-block-comment-ender))
-      "a\\`"))
+      "a\\`"))				; Doesn't match anything.
 (c-lang-defvar c-block-comment-ender-regexp
 	       (c-lang-const c-block-comment-ender-regexp))
 
@@ -1522,7 +1522,7 @@ properly."
   ;; language)
   t (if (c-lang-const c-block-comment-starter)
 	(regexp-quote (c-lang-const c-block-comment-starter))
-      "a\\`"))
+      "a\\`"))				; Doesn't match anything.
 (c-lang-defvar c-block-comment-start-regexp
   (c-lang-const c-block-comment-start-regexp))
 
@@ -1531,7 +1531,7 @@ properly."
   ;; language; it does in all 7 CC Mode languages).
   t (if (c-lang-const c-line-comment-starter)
 	(regexp-quote (c-lang-const c-line-comment-starter))
-      "a\\`"))
+      "a\\`"))				; Doesn't match anything.
 (c-lang-defvar c-line-comment-start-regexp
 	       (c-lang-const c-line-comment-start-regexp))
 
@@ -1546,7 +1546,7 @@ properly."
 
 (c-lang-defconst c-doc-comment-start-regexp
   "Regexp to match the start of documentation comments."
-  t    "a\\`"
+  t    "a\\`"	; Doesn't match anything.
   ;; From font-lock.el: `doxygen' uses /*! while others use /**.
   (c c++ objc) "/\\*[*!]"
   java "/\\*\\*"
@@ -3001,7 +3001,7 @@ Note that Java specific rules are currently applied to tell this from
   "Regexp matching a keyword that is followed by a colon, where
   the whole construct can precede a declaration.
   E.g. \"public:\" in C++."
-  t "a\\`"
+  t "a\\`"				; Doesn't match anything.
   c++ (c-make-keywords-re t (c-lang-const c-protection-kwds)))
 (c-lang-defvar c-decl-start-colon-kwd-re
   (c-lang-const c-decl-start-colon-kwd-re))
@@ -3379,7 +3379,7 @@ list."
 (c-lang-defconst c-pre-id-bracelist-key
   "A regexp matching tokens which, preceding an identifier, signify a bracelist.
 "
-  t "a\\`"
+  t "a\\`"				; Doesn't match anything.
   c++ "new\\([^[:alnum:]_$]\\|$\\)\\|&&?\\(\\S.\\|$\\)")
 (c-lang-defvar c-pre-id-bracelist-key (c-lang-const c-pre-id-bracelist-key))
 
@@ -3435,7 +3435,7 @@ the invalidity of the putative template construct."
 	 ;; before the '{' of the enum list, to avoid searching too far.
 	 "[^][{};/#=]*"
 	 "{")
-      "a\\`"))
+      "a\\`"))				; Doesn't match anything.
 (c-lang-defvar c-enum-clause-introduction-re
 	       (c-lang-const c-enum-clause-introduction-re))
 
@@ -3551,7 +3551,7 @@ i.e. before \":\".  Only used if `c-recognize-colon-labels' is set."
   "Regexp matching things that can't occur two symbols before a colon in
 a label construct.  This catches C++'s inheritance construct \"class foo
 : bar\".  Only used if `c-recognize-colon-labels' is set."
-  t "a\\`"				; matches nothing
+  t "a\\`"				; Doesn't match anything.
   c++ (c-make-keywords-re t '("class")))
 (c-lang-defvar c-nonlabel-token-2-key (c-lang-const c-nonlabel-token-2-key))