C++ ifstream error using string as opening file path.

c++ ifstream
Mark picture Mark · Jun 12, 2011 · Viewed 90.5k times · Source

I have: 

string filename: 
ifstream file(filename);

The compilers complains about no match between ifstream file and a string. Do I need to convert filename 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

Seth Carnegie picture Seth Carnegie · Jun 12, 2011

Change

ifstream file(filename);

to

ifstream file(filename.c_str());

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

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