Perfect! That works!
I will compare it with my thousand-sep rule/grammar in boost::spirit, a
little benchmark to find out which one is faster. Do have
experiences/results with boost::spirit vs. boost::xpressive?
Thank you very much. Have a nice weekend.
2011/9/9 Eric Niebler
#include <string> #include <iostream> #include <iomanip> #include
#include namespace xp = boost::xpressive; int main() { using namespace xp; placeholder<double> result; sregex double_ = ~after(_d) >> // a number with no group separators, and either a period or comma // for fraction separator (+_d)[result = as<double>(_)] >> !((set=',','.') >> (_d >> _d)[result += as<int>(_)/100.0]) >> ~before(set[_d|','|'.']) // A number with optional group separators | repeat<1,3>(_d)[result = as<int>(_)] >> ( // ... with comma group separators and period fraction separator *(',' >> repeat<3>(_d)[result *= 1000, result += as<int>(_)]) >> !('.' >> (_d >> _d)[result += as<int>(_)/100.0]) >> ~before(set[_d|','|'.']) // ... with period group separators and comma fraction separator | *('.' >> repeat<3>(_d)[result *= 1000, result += as<int>(_)]) >> !(',' >> (_d >> _d)[result += as<int>(_)/100.0]) >> ~before(set[_d|','|'.']) );
std::string str; double d = 0.0; smatch what; what.let(result = d); std::cout << std::fixed << std::setprecision(2); while (std::getline(std::cin, str)) { if (regex_search(str, what, double_)) { std::cout << "Double = " << d << '\n'; } else { std::cout << "No match\n"; } } }