encountered an invalid data type.
=item Both or neither range ends should be Unicode in regex; marked by
-<-- HERE in m/%s/
+S<<-- HERE> in m/%s/
(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
could be defined by a translator installed into C<$^H{charnames}>.
See L<charnames/CUSTOM ALIASES>.
-=item \C is deprecated in regex; marked by <-- HERE in m/%s/
+=item \C is deprecated in regex; marked by S<<-- HERE> in m/%s/
(D deprecated, regexp) The \C character class is deprecated, and will
become a compile-time error in a future release of perl (tentatively
(F) The parser found inconsistencies either while attempting
to define an overloaded constant, or when trying to find the
character name specified in the C<\N{...}> escape. Perhaps you
-forgot to load the corresponding L<overload> pragma?.
+forgot to load the corresponding L<overload> pragma?
=item :const is experimental
most likely cause of this error is that you left out a parenthesis inside
of the C<....> part.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item %s defines neither package nor VERSION--version check failed
(F) You used a pattern that nested too many EVAL calls without consuming
any text. Restructure the pattern so that text is consumed.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item Excessively long <> operator
with the B<-D> option with no flags to see the list of acceptable values.
See also L<perlrun/-Dletters>.
+=item Invalid quantifier in {,} in regex; marked by S<<-- HERE> in m/%s/
+
+(F) The pattern looks like a {min,max} quantifier, but the min or max
+could not be parsed as a valid number - either it has leading zeroes,
+or it represents too big a number to cope with. The S<<-- HERE> shows
+where in the regular expression the problem was discovered. See L<perlre>.
+
=item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
(F) The range specified in a character class had a minimum character
(F) Your machine doesn't implement the sockatmark() functionality,
neither as a system call nor an ioctl call (SIOCATMARK).
-=item "%s" is more clearly written simply as "%s" in regex; marked by <-- HERE in m/%s/
+=item '%s' is an unknown bound type in regex; marked by S<<-- HERE> in m/%s/
+
+(F) You used C<\b{...}> or C<\B{...}> and the C<...> is not known to
+Perl. The current valid ones are given in
+L<perlrebackslash/\b{}, \b, \B{}, \B>.
+
+=item "%s" is more clearly written simply as "%s" in regex; marked by S<<-- HERE> in m/%s/
(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
class loses its specialness: it matches almost everything, which is
probably not what you want.
-=item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked
-by S<<-- HERE> in m/%s/
+=item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked by <-- HERE in m/%s/
(F) Named Unicode character escapes (C<\N{...}>) may return a
multi-character sequence. Even though a character class is
(F) Fully qualified variable names are not allowed in "our"
declarations, because that doesn't make much sense under existing
-semantics. Such syntax is reserved for future extensions.
+rules. Such syntax is reserved for future extensions.
=item No Perl script found in input
=item Operation "%s" returns its argument for non-Unicode code point 0x%X
-(S non_unicode) You performed an operation requiring Unicode semantics
+(S non_unicode) You performed an operation requiring Unicode rules
on a code point that is not in Unicode, so what it should do is not
defined. Perl has chosen to have it do nothing, and warn you.
=item Operation "%s" returns its argument for UTF-16 surrogate U+%X
(S surrogate) You performed an operation requiring Unicode
-semantics on a Unicode surrogate. Unicode frowns upon the use
+rules on a Unicode surrogate. Unicode frowns upon the use
of surrogates for anything but storing strings in UTF-16, but
-semantics are (reluctantly) defined for the surrogates, and
+rules are (reluctantly) defined for the surrogates, and
they are to do nothing for this operation. Because the use of
surrogates can be dangerous, Perl warns.
no warnings "experimental::autoderef";
-=item POSIX class [:%s:] unknown in regex; marked by S<< <-- HERE in m/%s/ >>
+=item POSIX class [:%s:] unknown in regex; marked by S<<-- HERE> in m/%s/
(F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
shows whereabouts in the regular expression the problem was discovered.
no warnings "experimental::autoderef";
-=item Quantifier follows nothing in regex; marked by S<< <-- HERE in m/%s/ >>
+=item Quantifier follows nothing in regex; marked by S<<-- HERE> in m/%s/
(F) You started a regular expression with a quantifier. Backslash it if
you meant it literally. The S<<-- HERE> shows whereabouts in the regular
expression the problem was discovered. See L<perlre>.
-=item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in
-m/%s/
+=item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in m/%s/
(F) There is currently a limit to the size of the min and max values of
the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
by prepending "0" to your numbers.
=item Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
-"a-z" in regex; marked by <-- HERE in m/%s/
+"a-z" in regex; marked by S<<-- HERE> in m/%s/
(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
must be all digits, or all uppercase letters, or all lowercase letters.
=item Ranges of digits should be from the same group in regex; marked by
-<-- HERE in m/%s/
+S<<-- HERE> in m/%s/
(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
you wanted to have the character with ordinal 7 inserted into the regular
expression, prepend zeroes to make it three digits long: C<\007>
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item Reference to nonexistent named group in regex; marked by S<<-- HERE>
such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
spelled correctly both in the backreference and the declaration.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item Reference to nonexistent or unclosed group in regex; marked by
are not at least seven sets of closed capturing parentheses in the
expression before where the C<\g{-7}> was located.
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered.
=item regexp memory corruption
(R&NAME) true if directly inside named capture
(DEFINE) always false; for defining named subpatterns
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
=item Switch (?(condition)... not terminated in regex; marked by
This is to prevent the problem of one module changing the array base out
from under another module inadvertently. See L<perlvar/$[> and L<arybase>.
+=item The bitwise feature is experimental
+
+(S experimental::bitwise) This warning is emitted if you use bitwise
+operators (C<& | ^ ~ &. |. ^. ~.>) with the "bitwise" feature enabled.
+Simply suppress the warning if you want to use the feature, but know
+that in doing so you are taking the risk of using an experimental
+feature which may change or be removed in a future Perl version:
+
+ no warnings "experimental::bitwise";
+ use feature "bitwise";
+ $x |.= $y;
+
=item The crypt() function is unimplemented due to excessive paranoia.
(F) Configure couldn't find the crypt() function on your machine,
Check the #! line, or manually feed your script into Perl yourself.
=item Unescaped left brace in regex is deprecated, passed through in regex;
-marked by <-- HERE in m/%s/
+marked by S<<-- HERE> in m/%s/
(D deprecated, regexp) You used a literal C<"{"> character in a regular
expression pattern. You should change to use C<"\{"> instead, because a
(R&NAME) true if directly inside named capture
(DEFINE) always false; for defining named subpatterns
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
=item Unknown Unicode option letter '%c'
if ($string =~ /$pattern/) { ... }
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
=item Useless localization of %s
if ($string =~ /$pattern/o) { ... }
-The <-- HERE shows whereabouts in the regular expression the problem was
+The S<<-- HERE> shows whereabouts in the regular expression the problem was
discovered. See L<perlre>.
=item Useless use of attribute "const"
form if you wish to use an empty line as the terminator of the
here-document.
+=item Use of \b{} for non-UTF-8 locale is wrong. Assuming a UTF-8 locale
+
+(W locale) You are matching a regular expression using locale rules,
+and a Unicode boundary is being matched, but the locale is not a Unicode
+one. This doesn't make sense. Perl will continue, assuming a Unicode
+(UTF-8) locale, but the results could well be wrong except if the locale
+happens to be ISO-8859-1 (Latin1) where this message is spurious and can
+be ignored.
+
=item Use of chdir('') or chdir(undef) as chdir() deprecated
(D deprecated) chdir() with no arguments is documented to change to
these circumstances, Perl discards all but the first character
of the returned sequence, which is not likely what you want.
+=item Using /u for '%s' instead of /%s in regex; marked by S<<-- HERE> in m/%s/
+
+(W regexp) You used a Unicode boundary (C<\b{...}> or C<\B{...}>) in a
+portion of a regular expression where the character set modifiers C</a>
+or C</aa> are in effect. These two modifiers indicate an ASCII
+interpretation, and this doesn't make sense for a Unicode defintion.
+The generated regular expression will compile so that the boundary uses
+all of Unicode. No other portion of the regular expression is affected.
+
=item Using !~ with %s doesn't make sense
(F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
(W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
one), a multi-byte character was encountered. Perl considers this
-character to be the specified Unicode code point. Combining non-UTF8
+character to be the specified Unicode code point. Combining non-UTF-8
locales and Unicode is dangerous. Almost certainly some characters
will have two different representations. For example, in the ISO 8859-7
(Greek) locale, the code point 0xC3 represents a Capital Gamma. But so