$+[0] is the offset of the end of the last successfull match.
C<$+[>I<n>C<]> is the offset of the end of the substring matched by
-I<n>-th subpattern.
+I<n>-th subpattern, or undef if the subpattern did not match.
Thus after a match against $_, $& coincides with C<substr $_, $-[0],
-$+[0]>. Similarly, C<$>I<n> coincides with C<substr $_, $-[>I<n>C<],
-$+[>I<0>C<]> if C<$-[>I<n>C<]> is defined, and $+ conincides with
-C<substr $_, $-[-1], $+[-1]>. One can use C<$#+> to find the last
-matched subgroup in the last successful match. Compare with L<"@-">.
+$+[0] - $-[0]>. Similarly, C<$>I<n> coincides with C<substr $_, $-[>I<n>C<],
+$+[>I<n>C<] - $-[>I<n>C<]> if C<$-[>I<n>C<]> is defined, and $+ coincides with
+C<substr $_, $-[$#-], $+[$#-]>. One can use C<$#+> to find the number
+of subgroups in the last successful match. Note the difference with
+C<$#->, which is the last I<matched> subgroup. Compare with L<"@-">.
=item $MULTILINE_MATCHING
$-[0] is the offset of the start of the last successfull match.
C<$-[>I<n>C<]> is the offset of the start of the substring matched by
-I<n>-th subpattern.
+I<n>-th subpattern, or undef if the subpattern did not match.
Thus after a match against $_, $& coincides with C<substr $_, $-[0],
-$+[0]>. Similarly, C<$>I<n> coincides with C<substr $_, $-[>I<n>C<],
-$+[>I<0>C<]> if C<$-[>I<n>C<]> is defined, and $+ conincides with
-C<substr $_, $-[-1], $+[-1]>. One can use C<$#-> to find the last
-matched subgroup in the last successful match. Compare with L<"@+">.
+$+[0] - $-[0]>. Similarly, C<$>I<n> coincides with C<substr $_, $-[>I<n>C<],
+$+[>I<n>C<] - $-[>I<n>C<]> if C<$-[>I<n>C<]> is defined, and $+ coincides with
+C<substr $_, $-[$#-], $+[$#-]>. One can use C<$#-> to find the last
+matched subgroup in the last successful match. Note the difference with
+C<$#+>, which is the number of subgroups in the regular expression. Compare
+with L<"@+">.
=item format_name HANDLE EXPR