//Program to create a file called cplusad.dat which is identical to the file
//cad.dat, except that all occurrences of 'C' are replaced by "C++".
//Assumes that the uppercase letter 'C' does not occur in cad.dat, except
//as the name of the C programming language.

#include <fstream.h>
#include <iostream.h>
#include <stdlib.h>

void add_plus_plus(ifstream& in_stream, ofstream& out_stream);
//Precondition: in_stream has been connected to an input file with open.
//out_stream has been connected to an output file with open.
//Postcondition: The contents of the file connected to in_stream have been
//copied into the file connected to out_stream, but with each 'C' replaced
//by "C++". (The files are not closed by this function.)

int main()
{
    ifstream fin;
    ofstream fout;

    cout << "Begin editing files.\n";

    fin.open("cad.dat");
    if (fin.fail())
    {
        cout << "Input file opening failed.\n";
        exit(1);
    }

    fout.open("cplusad.dat");
    if (fout.fail())
    {
        cout << "Output file opening failed.\n";
        exit(1);
    }

    add_plus_plus(fin, fout);

    fin.close();
    fout.close();

    cout << "End of editing files.\n";
    return 0;
}

void add_plus_plus(ifstream& in_stream, ofstream& out_stream)
{
    char next;

    in_stream.get(next);
    while (! in_stream.eof())
    {
         if (next == 'C')
            out_stream << "C++";
        else
            out_stream << next;

       in_stream.get(next);
    }
}