c++ regex 正则类例子及其gcc4.8报错

参考：c++ regex类

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例子

#include <iostream>
#include <string>
#include <regex>
using namespace std;
int main(void) 
{
	cout << "hello world" <<endl;
	std::string str("zh_CN");
	std::string pref ("zh-CN");
	cout << "str: "<< str <<endl;
	cout << "perf: " <<pref <<endl;

	cout << "compare: "<<str.compare("zh")<<endl;
	
	size_t sep = str.find ('_');
	std::regex locale(str.substr(0,sep)+ "-[A-Za-z]*"  +str.substr(sep+1));	 //new 一个正在
	
	cout << "create locale ok"<<endl;
	cout << "is same: "<< std::regex_match("zh-CN",locale) << endl;
	return 0;
}

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报错记录
1.使用g++ 编译 g++ -o regex regex.cpp

 error: #error This file requires compiler and library support for the ISO C++ 2011 standard. This support is currently experimental, and must be enabled with the -std=c++11 or -std=gnu++11 compiler options

解决：是由于新版c++11 需要 -std=c++11

2.使用 g++ -o regex regex.cpp -std=c++11
./regex 后出现段错误

terminate called after throwing an instance of 'std::regex_error'
  what():  regex_error
Aborted (core dumped)

查网上原因是因为gcc 4.8 对新特性c++11的regex不完全支持
见参考Is gcc 4.8 or earlier buggy about regular expressions?

我的g++ 版本

g++ --version
g++ (Ubuntu 4.8.4-2ubuntu1~14.04.4) 4.8.4
Copyright (C) 2013 Free Software Foundation, Inc.

更换g++ 4.9试试 就可以了

/usr/bin/g++-4.9 -o regex regex.cpp -std=c++11
~/test_2020.01.07/c++_func$ ./regex 
hello world
str: zh_CN
perf: zh-CN
compare: 3
create locale ok
is same: 1