I'm using c++ to manipulate txt files. I need to write some numbers with a certain precision so I'm doing:
ofstrem file;
file.open(filename, ios::app);
file.precision(6);
file.setf(ios::fixed, ios::floafield);
//writing number on the file.....
now I need to write other stuff, so I need to reset precision. how can I do it?
Answer
Retrieve the stream's original precision value first with precision(), store it, change it, do your insertions, then change it back to the stored value.
int main() {
std::stringstream ss;
ss << 1.12345 << " ";
std::streamsize p = ss.precision();
ss.precision(2);
ss << 1.12345 << " ";
ss.precision(p);
ss << 1.12345;
cout << ss.str(); // 1.12345 1.1 1.12345
}