What's different between strm.clear() and strm.setstate(old_state)?

code1

std::istream &func1(std::istream &in) {
    auto old_state = in.rdstate();
    std::cout << old_state << std::endl;
    std::string s;
    while(in >> s) {
        std::cout << s << std::endl;
    }
    in.setstate(old_state);
    std::cout << in.rdstate() << std::endl;
    //in.clear();
    return in;
}

when execute this function, the output: 0 1 1 6 // ctrl+d 6 code2

std::istream &func2(std::istream &in) {
    auto old_state = in.rdstate();
    std::cout << old_state << std::endl;
    std::string s;
    while(in >> s) {
        std::cout << s << std::endl;
    }
    in.setstate(old_state);
    std::cout << in.rdstate() << std::endl;
    in.clear();
    return in;
}

when execute this function, the output: 0 1 1 6 // ctrl+d 0 I know the clear() reset the condition values in stream to valid state.But in func1, I have used setstate(old_state), why the output is still 6?