passing ios::flag as a parameter ..

I have function saveData() which writes to a text file. I would like to tell it whether to append ios::app or create new ios:ut ... How do i pass these flags as a parameter to saveData(...)?

One option is to have a std::ostream as the parameter. If you really want to open the file according to a filename and format flags then std::ios::fmtflags should be the type of the format flags parameter.

Originally Posted by laserlight

One option is to have a std::ostream as the parameter. If you really want to open the file according to a filename and format flags then std::ios::fmtflags should be the type of the format flags parameter.

should it be this?

Code:

void saveData(std::ios::fmtflags flag) 
{
      	ofstream outfile;
	char filename[MAX_PATH] = "contract.txt";
	outfile.open(filename, flag);
}

Originally Posted by csonx_p

should it be this?

It is probably correct but if you really need the filename variable, it would be better to write it as:

Code:

char filename[MAX_PATH] = "contract.txt";
ofstream outfile(filename, flag);

Actually, if you need filename, why not make it a std::string?

Originally Posted by laserlight

Actually, if you need filename, why not make it a std::string?

because

Code:

void open ( const char * filename, ios_base::openmode mode = ios_base::out );

Use the c_str() member function, e.g.,

Code:

std::string filename = "contract.txt";
ofstream outfile(filename.c_str(), flag);

EDIT:
By the way, it looks like I got it wrong: the std::ios::fmtflags is for format flags (duh). On the other hand, the source you quoted gives std::ios_base:penmode, so perhaps you can try std::ios::openmode as the type.

Originally Posted by csonx_p

because

Code:

void open ( const char * filename, ios_base::openmode mode = ios_base::out );

You can call c_str() on the string to get a char *...