c++ convert time_t to string and back again

Question

I want to convert a time_t to a string and back again.
I'd like to convert the time to a string using ctime().
I can't seem to find anything on google or the time.h header file, any ideas?
Basically what I'm trying to do is store a date in a file, and then read it back so I can use it as a time_t again.
Also, no library references outside of std,mfc.
One more note, this will have to function on Windows xp and above and that's it.

Edit

All I want to do is convert a time_t into a string(I don't care if it's human readable) and then convert it back to a time_t. I'm basically just trying to store the time_t into a file and read it again(but I don't want any code for that, as there will be more info in the file besides a time_t).

Answer 1

You'll have to write your own function to do that. These functions convert any primitive type (or any type which overloads operator<< and/or operator>>) to a string, and viceversa:

template<typename T>
std::string StringUtils::toString(const T &t) {
    std::ostringstream oss;
    oss << t;
    return oss.str();
}

template<typename T>
T StringUtils::fromString( const std::string& s ) {
    std::istringstream stream( s );
    T t;
    stream >> t;
    return t;
}

Answer 2

ctime() returns a pointer to a character buffer that uses a specific formatting. You could use sprintf() to parse such a string into its individual portions, store them in a struct tm, and use mktime() to convert that to a time_t.