Spirit sequence-of-sequences: struct vs. string

gistfile1.txt

// To see if a rule whose attribute is sequence-of-sequence can make appends happen somehow

#include <string>
#include <vector>

#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/adapt_struct.hpp>

struct tiny {
    std::string thing;
    int         i;
};
BOOST_FUSION_ADAPT_STRUCT(
    tiny,
    (std::string, thing)
    (int, i)
)

using string_it_t = std::string::const_iterator;

int main() {
    using namespace boost::spirit;
    using namespace boost::spirit::qi;


// STRING CASE
/*
    rule<string_it_t, std::vector<std::string>()> l1, l2;
    l1 = +qi::string("foo") ;
*/

// STRUCT CASE
    rule<string_it_t, std::vector<tiny>()> l1, l2;
    l1 = +(qi::string("foo") >> qi::int_);

// in both
    l2 = *l1 ;     // fails to compile with tiny, succeeds with std::string

}