/* The following code example is taken from the book * "The C++ Standard Library - A Tutorial and Reference" * by Nicolai M. Josuttis, Addison-Wesley, 1999 * * (C) Copyright Nicolai M. Josuttis 1999. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */#include <string>       // for strings#include <iostream>     // for I/O#include <fstream>      // for file I/O#include <iomanip>      // for setw()#include <cstdlib>      // for exit()using namespace std;// forward declarationsvoid writeCharsetToFile (const string& filename);void outputFile (const string& filename);int main (){    writeCharsetToFile("charset.out");    outputFile("charset.out");}void writeCharsetToFile (const string& filename){    // open output file    ofstream file(filename.c_str());    // file opened?    if (! file) {        // NO, abort program        cerr << "can't open output file \"" << filename << "\""             << endl;        exit(EXIT_FAILURE);    }    // write character set    for (int i=32; i<256; i++) {        file << "value: " << setw(3) << i << "   "             << "char:  " << static_cast<char>(i) << endl;    }}   // closes file automaticallyvoid outputFile (const string& filename){    // open input file    ifstream file(filename.c_str());    // file opened?    if (! file) {        // NO, abort program        cerr << "can't open input file \"" << filename << "\""             << endl;        exit(EXIT_FAILURE);    }    // copy file contents to cout    char c;    while (file.get(c)) {        cout.put(c);    }}   // closes file automatically