> structures of type <i>regmatch_t</i>, containing the
members <i>rm_so</i> and <i>rm_eo</i>. These contain the byte offset to the first
character of each substring and the offset to the first character after the end
of each substring, respectively. The 0th element of the vector relates to the
entire portion of <i>string</i> that was matched; subsequent elements relate to
the capturing subpatterns of the regular expression. Unused entries in the
array have both structure members set to -1.
</p>
<p>
<i>regma