c++ - regex("(abc|aa.*|bb.*)") Vs regex("(aa.*|bb.*|cc.*)"); -

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this question has answer here:

i encounter weird problem when using regex in c++11 (ubuntu 14.4 ,gcc 4.8.2)

#include <iostream> #include <regex> using namespace std; int main() {     regex r("(abc|aa.*|bb.*)");     cout<<regex_match("bb11",r)<<endl;  //return false     cout<<regex_match("aa11",r)<<endl;  //return true     cout<<regex_match("abc",r)<<endl;   //return true     return 0; }

while

int main() {     regex r("(aa.*|bb.*|cc.*)");     cout<<regex_match("bb11",r)<<endl;  //return true     cout<<regex_match("aa11",r)<<endl;  //return true     cout<<regex_match("abc",r)<<endl;   //return false     return 0; }

i wondering why "bb11" got different result?

std::regex not supported in gcc until 4.9.

in 4.8.2 you'll sorts of odd behaviour.


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