--- a/src/ov-str-mat.cc	Wed Apr 12 18:54:25 2006 +0000
+++ b/src/ov-str-mat.cc	Wed Apr 12 19:23:26 2006 +0000
@@ -33,20 +33,21 @@
 #include "mach-info.h"
 #include "mx-base.h"
 
+#include "defun.h"
+#include "byte-swap.h"
+#include "gripes.h"
+#include "ls-oct-ascii.h"
+#include "ls-hdf5.h"
+#include "ls-utils.h"
 #include "oct-obj.h"
 #include "oct-stream.h"
 #include "ops.h"
 #include "ov-scalar.h"
 #include "ov-re-mat.h"
 #include "ov-str-mat.h"
-#include "gripes.h"
 #include "pr-output.h"
 #include "pt-mat.h"
-
-#include "byte-swap.h"
-#include "ls-oct-ascii.h"
-#include "ls-hdf5.h"
-#include "ls-utils.h"
+#include "utils.h"
 
 DEFINE_OCTAVE_ALLOCATOR (octave_char_matrix_str);
 DEFINE_OCTAVE_ALLOCATOR (octave_char_matrix_sq_str);
@@ -54,6 +55,13 @@
 DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_char_matrix_str, "string", "char");
 DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_char_matrix_sq_str, "sq_string", "char");
 
+// If TRUE, warn for operations like
+//
+//   octave> 'abc' + 0
+//   97 98 99
+//
+static bool Vwarn_str_to_num;
+
 static octave_value *
 default_numeric_conversion_function (const octave_value& a)
 {
@@ -756,6 +764,35 @@
 
 #endif
 
+static int
+warn_str_to_num (void)
+{
+  Vwarn_str_to_num = check_preference ("warn_str_to_num");
+
+  return 0;
+}
+
+void
+symbols_of_ov_str_mat (void)
+{
+  DEFVAR (warn_str_to_num, false, warn_str_to_num,
+    "-*- texinfo -*-\n\
+@defvr {Built-in Variable} warn_str_to_num\n\
+If the value of @code{warn_str_to_num} is nonzero, a warning is printed\n\
+for implicit conversions of strings to their numeric ASCII equivalents.\n\
+For example,\n\
+@example\n\
+@group\n\
+\"abc\" + 0\n\
+     @result{} 97 98 99\n\
+@end group\n\
+@end example\n\
+elicits a warning if @code{warn_str_to_num} is nonzero.  The default\n\
+value is 0.\n\
+@end defvr");
+}
+
+
 /*
 ;;; Local Variables: ***
 ;;; mode: C++ ***