Regex in C++: Requires compiler support error

Question

I'm trying to use regex in C++. The following is my code:

#include<iostream>
#include<stdlib.h>
#include<string.h>
#include<regex>
using namespace std;

int main(int argc, char** argv) {
    string A = "Hello!";
    regex pattern = "(H)(.*)";
    if (regex_match(A, pattern)) {
        cout << "It worked!";
    }
    return 0;
}

But I'm encountering this error :

In file included from /usr/lib/gcc/i686-pc-cygwin/4.5.3/include/c++/regex:35:0,
                 from main.cpp:12:
/usr/lib/gcc/i686-pc-cygwin/4.5.3/include/c++/bits/c++0x_warning.h:31:2: error: #error This file requires compiler and library support for the upcoming ISO C++ standard, C++0x. This support is currently experimental, and must be enabled with the -std=c++0x or -std=gnu++0x compiler options.

How can this be solved and what is wrong?

Perhaps dup to http://stackoverflow.com/questions/4716680/c0x-regex-in-gcc — ZhangChn, Dec 12 '12 at 09:48

score 6 · Accepted Answer · answered Dec 12 '12 at 09:45

6

and must be enabled with the -std=c++0x or -std=gnu++0x compiler options

Add one of those options, -std=c++0x or -std=gnu++0x, to your compiler command:

g++ -std=c++0x ...

Note if std::regex is not supported see boost::regex for an alternative.

answered Dec 12 '12 at 09:45

hmjd

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How exactly do I do that? Thanks! – Enigman Dec 12 '12 at 09:46
Oh. I'm not using the terminal to compile and run my code. I'm using netbeans. – Enigman Dec 12 '12 at 09:48
1

@Enigman, I don't use NetBeans. Google for how to add compiler options in NetBeans or search the NetBeans manual should provide you with a solution. – hmjd Dec 12 '12 at 09:50
Yeah. I shouldn't have asked that here! Sorry. Will do that. – Enigman Dec 12 '12 at 09:51

Tom Macdonald · Answer 2 · 2012-12-12T10:07:51.163

2

It looks like you are trying to use the regex class, which is part of the new C++11 standard, but not telling the compiler to compile to that standard.

Add -std=c++0x to your compiler flags and try again.

EDIT : As the gcc implementation status page shows, the regex support in gcc is far from complete. So even adding the right flag wont help yet. If you need regex support, you could try boost.

edited Dec 12 '12 at 10:07

answered Dec 12 '12 at 09:46

Tom Macdonald

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How do I add it to my 'compiler flags?' I'm using NetBeans. Is there an option here that lets me do that? – Enigman Dec 12 '12 at 09:47
project properties -> Build -> C++ Compiler -> Additional Options I believe. – Tom Macdonald Dec 12 '12 at 09:55
I've done that. Still there seems to be error. :( I tried the code given at http://www.cplusplus.com/reference/regex/regex_match/ too. – Enigman Dec 12 '12 at 09:57
See my edit. Regex support in the gcc C++11 implementation is not complete. – Tom Macdonald Dec 12 '12 at 10:08
@Enigman - don't bother. GCC's implementation of regular expressions is unusable. – Pete Becker Dec 12 '12 at 14:57

score 2 · Answer 3 · edited Sep 29 '15 at 16:01

2

Simply just add

g++ -std=gnu++0x <filename.cpp>

or

g++ -std=c++0x <filename.cpp>

It will work properly

edited Sep 29 '15 at 16:01

Artjom B.

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answered Sep 29 '15 at 11:42

abhisek

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Regex in C++: Requires compiler support error

3 Answers3