RegExp.match question

[Saaa]

const char[] re1 = `(re)1`;
const char[] re2 = `(re)2`;
char[] matchWrite(RegExp re)
{
writefln(re.match(1),`,`,re.match(2));
return "";
}
std.regexp.sub(`re1 re2`, re1~'|'~re2, &matchWrite, "g");

--- prints
re,
re,re // shouldn't this be `,re`?