I know two ways of getting regex matches from std::string, but I don't know how to get all matches with their respective offsets.
#include <string>
#include <iostream>
#include <regex>
int main() {
using namespace std;
string s = "123 apples 456 oranges 789 bananas oranges bananas";
regex r = regex("[a-z]+");
const sregex_token_iterator end;
// here I know how to get all occurences
// but don't know how to get starting offset of each one
for (sregex_token_iterator i(s.cbegin(), s.cend(), r); i != end; ++i) {
cout << *i << endl;
}
cout << "====" << endl;
// and here I know how to get position
// but the code is finding only first match
smatch m;
regex_search ( s, m, r );
for (unsigned i=0; i< m.size(); ++i) {
cout << m.position(i) << endl;
cout << m[i] << endl;
}
}
First of all, why token iterator? You don't have any marked subexpressions to iterate over.
Second, position() is a member function of a match, so:
#include <string>
#include <iostream>
#include <regex>
int main() {
std::string s = "123 apples 456 oranges 789 bananas oranges bananas";
std::regex r("[a-z]+");
for(std::sregex_iterator i = std::sregex_iterator(s.begin(), s.end(), r);
i != std::sregex_iterator();
++i )
{
std::smatch m = *i;
std::cout << m.str() << " at position " << m.position() << '\n';
}
}
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