C++ Spirit Boost: Making a input iterator into a forward iterator

Question

So I'm very new to Boost but I'm running into problems trying to do some of the most basic of things in my win32 application project in vs2010.

I have gone into my vs2010 project properties and made sure that my include files are looking in the right places, and when I build I don't get errors including hpp files from boost in my stdafx.h, however when I read the documentation on their site here: http://www.boost.org/doc/libs/1_43_0/libs/spirit/doc/html/spirit/support/multi_pass.html I just get a bunch of basic errors like multi_pass is undefined.

I only need boost for one thing, and that is to create a forward operator from my current input operator so I can pass it through a function. Below is the declaration for my input operator.

std::istreambuf_iterator<char> eof;

I found an alternative solution on that same page where the std::basic_istream_iterator is actually a forward operator but when I compile I get an error saying that basic_istream_iterator is not part of the std library.

In the end I'm just really new to iterators themselves and boost. I would like to know how I can get my input iterator transformed into a forward iterator so I can iterator through a file.

Answer 1

Like the commenter siad, you need to include the right support headers.

#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/support_multi_pass.hpp>

Howeever, the simplest way is:

 std::ifstream file("myfile.txt", std::ios::binary);
 file.unsetf(std::ios::skipws);

 // use the ready-made:

 boost::spirit::istream_iterator f(file), l;

 // parse!
 book ok = qi::parse(f, l, my_grammar);