c++ - Wrong use of fprintf? Getting exception First-chance exception -

i'm getting "first-chance exception @ 0x708a6b2e (msvcr120.dll)" in first line of print_bit_vector() in second execution. can tell why?

code:

void print_bit_vector(file* pfile, std::string title, std::vector<bool> bitvector) {     fprintf(pfile, "%s:\r\n", title);     int size = bitvector.size();     int = 0;     (i = 0; < size; i++) {         std::cout << << std::endl;     //for (bool bit : bitvector)         fprintf(pfile, "%d", bitvector.at(i));     }     fprintf(pfile, "\r\n"); }  void test() {     file * pfile;     pfile = fopen("c:\\...\\myfile.txt", "w");      bc bc("c:\\...\\example_test.txt");     std::vector<bool> key = std::vector<bool>(128, 0);     std::vector<bool> input = std::vector<bool>(128, 1);      print_bit_vector(pfile, "key", key);     print_bit_vector(pfile, "input", input); //exception inside execution of print_bit_vector(...)      bc.setinputsbyparty(1, key);     bc.setinputsbyparty(2, input);      std::vector<bool> outputs;     bc.compute(outputs);        print_bit_vector(pfile, "output", outputs);      fclose(pfile); } 

simply because %s in printf wants char const *, not std::string.

you can use title.c_str() char const * c++ string.