using namespace std;
#include <iostream>
#include <string>
#include <regex>
#include <iterator>
string escape( string s ) {
std::regex re ( "[\\[\\]\\/^$.|?*+(){}]" );
return std::regex_replace (s, re, "\\$0");
};
int main ()
{
cout << escape( "[]abc{}" );
return 0;
}
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