C++11 Regex Capture Groups By Name

regex c++11 capture-group
Travis Parks picture Travis Parks · Jun 2, 2013 · Viewed 13.1k times · Source

I am converting my boost-based regular expressions to C++11 regex. I have a capture group called url:

\s*?=\s*?(("(?<url>.*?)")|('?<url>.*?)'))

With boost, if you had an smatch you could call match.str("url") to get the capture group by name. With std::smatch, I am only seeing indexed sub-matches.

How can I get access to the url capture using the std::smatch class?

Answer

aaronman picture aaronman · Jun 3, 2013

You cannot name a capture group with the c++11 standard. C++11 regex conforms to the ECMAScript syntax. Here is a link that explains it all http://www.cplusplus.com/reference/regex/ECMAScript/. Even though this maybe disappointing if you think about it a true regular expression will not support this it is extra.

Related questions

Is gcc 4.8 or earlier buggy about regular expressions?

I am trying to use std::regex in a C++11 piece of code, but it appears that the support is a bit buggy. An example: #include <regex> #include <iostream> int main (int argc, const char * argv[]) { …

Read More
Difference between std::regex_match & std::regex_search?

Below program has been written to fetch the "Day" information using the C++11 std::regex_match & std::regex_search. However, using the first method returns false and second method returns true(expected). I read the documentation and already existing …

Read More
std::regex, to match begin/end of string

In JS regular expressions symbols ^ and $ designate start and end of the string. And only with /m modifier (multiline mode) they match start and end of line - position before and after CR/LF. But in std::regex/ECMAscript mode …

Read More