#include <iostream>
#include <string>
using namespace std;
int main() {
string s1("test\0test");
std::cout << s1 << std::endl;
std::cout << s1.c_str() << std::endl;
string s2("test");
s2 += '\0';
s2 += "test";
std::cout << s2 << std::endl;
std::cout << s2.c_str() << std::endl;
}
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