+(eval-and-compile
+ (when (string-match "windows-nt\\|os/2\\|emx\\|cygwin"
+ (symbol-name system-type))
+ (defun subst-char-in-region (START END FROMCHAR TOCHAR &optional NOUNDO)
+ "From START to END, replace FROMCHAR with TOCHAR each time it occurs.
+If optional arg NOUNDO is non-nil, don't record this change for undo
+and don't mark the buffer as really changed.
+Both characters must have the same length of multi-byte form."
+ (let ((original-buffer-undo-list buffer-undo-list)
+ (modified (buffer-modified-p)))
+ (if NOUNDO
+ (setq buffer-undo-list t))
+ (goto-char START)
+ (let ((from (char-to-string FROMCHAR))
+ (to (char-to-string TOCHAR)))
+ (while (search-forward from END t)
+ (replace-match to t t)))
+ (if NOUNDO
+ (progn (setq buffer-undo-list original-buffer-undo-list)
+ (set-buffer-modidifed-p modified)))))))
+