c++ - ifstream reading in blanks when there is data in file -


i'm trying read in data text file using c++ ifstream , reason code below doesn't work. file contains 2 numbers separated space. code doesn't print out. explain me wrong?

#include <iostream> #include <string> #include <fstream> using namespace std;  void readintoadjmat(string fname) {     ifstream in(fname.c_str());     string race, length;     in >> race >> length;     cout << race << ' ' << length << endl;       in.close(); }  int main(int argc, char *argv[]) {     readintoadjmat("maze1.txt"); }

you should test interactions external entities successful:

std::ifstream in(fname.c_str()); std::string race, length; if (!in) {     throw std::runtime_error("failed open '" + fname + "' reading"); } if (in >> race >> length) {     std::cout << race << ' ' << length << '\n'; } else {     std::cerr << "warning: failed read file content\n"; }

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