#include <iostream>
#include <cstring>
#include <regex>

using namespace std;

int main () {
    std::string str1 = "a/b/c[2]/d";
    std::string str2 = R"(a/b/c\[2]/d)";
    std::regex e(str2);

    std::cout << "str1 = " << str1 << std::endl;
    std::cout << "str2 = " << str2 << std::endl;
    if (regex_search(str1, e)) {
        std::cout << "matched" << std::endl;
    }
}