I'm having some trouble integrating a class with iostream parsing support into a spirit parser. The example below (modified from the Spirit examples) demonstrates the problem. If I attempt to parse ONLY the custom class, it succeeds as shown by the first parse and call to assert. If I attempt to parse the custom class as well as (in this case) a comma and float, the parser fails.
Could anyone cast light on why this would be? If I use spirit parsers instead of the stream parser, I can make the second example work, but this defeats the purpose of using the stream_parser.
I've enabled rule debugging in my local example, and this shows that the custom parser consumes the entire contents of the string - however, the code shows that it shouldn't be doing this...
Any help appreciated!
Boost 1.44.0, gcc 4.1.1
#include <boost/spirit/include/qi.hpp>
struct complex
{
complex (double a = 0.0, double b = 0.0) : a(a), b(b) {}
double a,b;
};
std::istream& operator>> (std::istream& is, complex& z)
{
char lbrace = '\0', comma = '\0', rbrace = '\0';
is >> lbrace >> z.a >> comma >> z.b >> rbrace;
if (lbrace != '{' || comma != ',' || rbrace != '}')
is.setstate(std::ios_base::failbit);
return is;
}
int main( int argc, char**argv)
{
using namespace boost::spirit;
complex parsedComplex;
float parsedFloat;
bool result;
std::string str = "{1.0,2.5}";
std::string::iterator first = str.begin();
result = qi::phrase_parse(first,str.end(),
qi::stream_parser<char,complex>(), ascii::blank,parsedComplex);
assert(result && first==str.end()); // OK
str = "{1.0,2.5},123.456";
first = str.begin();
result = qi::phrase_parse(first,str.end(),
qi::stream_parser<char,complex>() >> qi::lit(',') >> qi::float_,
ascii::blank,parsedComplex,parsedFloat);
assert(result && first==str.end()); // FAILS
}
