数値パーサ

数値型に応じた組み込み型のパーサが用意されています。(namespace qi = boost::spirit::qi)

数値型(属性)	ルール
short	qi::short_
unsigned short	qi::ushort_
int	qi::int_
unsigned int	qi::uint_
long	qi::long_
unsigned long	qi::ulong_
long long	qi::long_long
unsigned long long	qi::ulong_long
float	qi::float_
double	qi::double_
long double	qi::long_double

doubleの値を読み込む

c++:double 例
#include <boost/spirit/include/qi.hpp>
#include <iostream>
#include <iomanip>
#include <string>

namespace qi = boost::spirit::qi;

int main() {
  std::string input = "8e5";
  double n;
  qi::parse( input.begin(), input.end(), qi::double_, n );
  std::cout << std::fixed << n << std::endl;
  return 0;
}

floatの値を読み込む

c++:float 例
#include <boost/spirit/include/qi.hpp>
#include <iostream>
#include <string>

namespace qi = boost::spirit::qi;

int main() {
  std::string input = "3.14125";
  float n;
  qi::parse( input.begin(), input.end(), qi::float_, n );
  std::cout << n << std::endl;
  return 0;
}

unsigned shortの値を読み込む

c++:unsigned short 例
#include <boost/spirit/include/qi.hpp>
#include <iostream>
#include <string>

namespace qi = boost::spirit::qi;

int main() {
  std::string input = "256";
  unsigned short n;
  qi::parse( input.begin(), input.end(), qi::ushort_, n );
  std::cout << n << std::endl;
  return 0;
}