How do you search a std::string for a substring in C++?

Question

I\'m trying to parse a simple string in C++. I know the string contains some text with a colon, followed immediately by a space, then a number. I\'d like to extract just t

Answer 1

I'm surprised that no one mentioned regular expressions. They were added as part of TR1 and are included in Boost as well. Here's the solution using regex's

typedef std::tr1::match_results Results;

std::tr1::regex re(":[[:space:]]+([[:digit:]]+)", std::tr1::regex::extended);
std::string     str("Sectors: 4095");
Results         res;

if (std::tr1::regex_search(str, res, re)) {
    std::cout << "Number found: " << res[1] << std::endl;
} else {
    std::cerr << "No number found." << std::endl;
}

It looks like a lot more work but you get more out of it IMHO.