Why did I use this knowledge in C++11 regex but The results are not consistent with expectations ?

[lin20220125]

such as:
cmatch reMatch;
regex reg("T.*d");
bool ret = regex_match("The car parked in the garage.", reMatch, reg);
if (ret)
{
for (auto index = 1; index < reMatch.size(); ++index)
{
cout << index << " ： " << reMatch[index].str() << endl;
}
}
why the ret is false ?