I was wondering if there is any guarantee about what does std::regex_search match when there are multiples match possibilities.
For example consider this simple regex that look for two positive integers: ([0-9]+).+([0-9]+).
If I search in this string <foo>123</foo><bar>456</bar>789<foobar> the two numbers matched could be:
123 and 456
456 and 789
123 and 789
2 and 56
4 and 5
a lot of other possibilities...
To get a guarrantee that only full numbers are matched I can change the regex to >([0-9]+)<.+>([0-9]+)< and now the two numbers matched could be:
123 and 456
456 and 789
123 and 789
Is there any guarantee about which of theses 3 possibilities will be returned by std::regex_search ?
If not, how to get the guarantee to get for example the first and shortest match (123 and 456) ?
std::string str = "<foo>123</foo><bar>456</bar>789<foobar>";
std::regex expr(">([0-9]+)<.+>([0-9]+)<");
std::smatch match;
if(!std::regex_search(str, match, expr))
puts("Not found");
printf("First number: %s\nSecond one: %s\n", match.str(1).c_str(), match.str(2).c_str());
The output I get is 123 and 789 but I expect 123 and 456.
