Why do I get a “no matching function” error when I open an fstream with the file name in a std::string?

Question

I am trying to write a program that reads in a list of strings from a file and checks what strings are missing from a second file and prints them to the screen. However, I am cu

Answer 1

This construct works for standard C++ 11 and newer compilers:

std::string filename;
//...
IN_FILE.open(filename);

This is basically the code you have now. However, the above will not work with pre-standard C++ 11 compilers (C++ 98, 03).

If you are compiling using a pre-standard C++ 11 compiler, then the code above should be:

std::string filename;
//...
IN_FILE.open(filename.c_str()); // Note the null-terminated const char *

Basically, the std::string version of open did not exist before C++ 11. Before C++ 11, you had to specify the name using a C-style, null-terminated string.

Thus the error you are seeing is because you are compiling in a version of C++ before C++ 11.