C ++ ifstream error, using a string as a path to open a file.

Question

I have:

string filename: ifstream file(filename); 

Compilers complain about the lack of correspondence between the ifstream file and the string. Do I need to convert a file name to something?

Here's the error:

 error: no matching function for call to 'std::basic_ifstream<char, std::char_traits<char> >::basic_ifstream(std::string&)' /usr/include/c++/4.4/fstream:454: note: candidates are: std::basic_ifstream<_CharT, _Traits>::basic_ifstream(const char*, std::_Ios_Openmode) [with _CharT = char, _Traits = std::char_traits<char>] 

Answer 1

Edit

 ifstream file(filename); 

to

 ifstream file(filename.c_str()); 

Since the constructor for ifstream takes const char* , not string pre-C ++ 11.

Answer 2

ifstream constructor expects const char* , so you need to do ifstream file(filename.c_str()); so that it works.

Answer 3

in C ++ - 11 it can also be std :: string. Therefore (installing C ++ - 11 and) changing the dialect of your project in C ++ - 11 can also fix the problem.