Why wont regex_search match anything?

Question

I can not seem to get the c++11 regex functions to work with even the most basic code. I must be missing something very basic, because this quick code keeps printing "No Match!" no matter what pattern I use.

std::string value = "foobar" ;
std::string pattern = "o" ;

std::regex re(pattern) ;
if (std::regex_search(value, re)) {
    std::cout << "Matched!" << std::endl ;
} else {
    std::cout << "No Match!" << std::endl ;
}

If it matters somehow, I compile (and get no errors) with

g++ -Wall -std=c++11 -o test test.cpp

`` is thoroughly broken on GCC/libstdc++. – Xeo Sep 11 '13 at 19:24 — Xeo, Sep 11 '13 at 19:24
`std::regex::match` apparently works as expected however – 6502 Sep 11 '13 at 19:29 — 6502, Sep 11 '13 at 19:29

6502 · Accepted Answer · 2013-09-11T19:39:34.787

1

Standard C++11 regular expression are not yet implemented in g++.

See http://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2011

It's not a "bug" in the sense of a mistake in the code... the only mistake is probably not breaking compile time with a message when seeing #include <regex>.

edited Sep 11 '13 at 19:39

answered Sep 11 '13 at 19:31

6502

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No. GCC regular expressions don’t work at all. Any apparently working code is pure coincidence. – Konrad Rudolph Sep 11 '13 at 19:34
That's some serious bug. Wow. Any idea when it's going to be fixed? Or am I using an old version and it's already been fixed? – Sep 11 '13 at 19:35
@ADCoon It’s not a bug, per se. The `` header is simply not yet implemented in GCC’s version of the standard library. They shouldn’t have shipped half-empty stubs but there you go. – Konrad Rudolph Sep 11 '13 at 19:36
@KonradRudolph I guess I'll have to wait or use Boost until they fix it. Annoying, though. – Sep 11 '13 at 19:42

Why wont regex_search match anything?

1 Answers1