What does getline do?

[MikiBelavista]

I am wrinting just part of the code
int main()
{
std::vector<std::vector<double>> v;
std::ifstream in( "pizd.dat" );
std::string record;

while ( std::getline( in, record ) )

So ifstream reads from the file the whole content.What is getline doing?

[LB]

std::ifstream is a stream. Nothing is read from the file unless you use the stream's input methods. One of those methods is calling std::getline on the stream.

[keskiverto]

The description of std::getline is in the reference documentation:
http://www.cplusplus.com/reference/string/string/getline/
http://en.cppreference.com/w/cpp/string/basic_string/getline