more/getting_started/detail/link-head.rst

Link Your Program to a Boost Library

To demonstrate linking with a Boost binary library, we'll use the following simple program that extracts the subject lines from emails. It uses the Boost.Regex library, which has a separately-compiled binary component. :

#include <boost/regex.hpp>
#include <iostream>
#include <string>

int main()
{
    std::string line;
    boost::regex pat( "^Subject: (Re: |Aw: )*(.*)" );

    while (std::cin)
    {
        std::getline(std::cin, line);
        boost::smatch matches;
        if (boost::regex_match(line, matches, pat))
            std::cout << matches[2] << std::endl;
    }
}

There are two main challenges associated with linking:

1. Tool configuration, e.g. choosing command-line options or IDE build settings.
2. Identifying the library binary, among all the build variants, whose compile configuration is compatible with the rest of your project.