format.cpp

Thingking in c++第二版

//: C02:Format.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Formatting functions
#include <fstream>
using namespace std;
#define D(A) T << #A << endl; A
ofstream T("format.out");

int main() {
  D(int i = 47;)
  D(float f = 2300114.414159;)
  char* s = "Is there any more?";

  D(T.setf(ios::unitbuf);)
//  D(T.setf(ios::stdio);)  // SOMETHING MAY HAVE CHANGED

  D(T.setf(ios::showbase);)
  D(T.setf(ios::uppercase);)
  D(T.setf(ios::showpos);)
  D(T << i << endl;) // Default to dec
  D(T.setf(ios::hex, ios::basefield);)
  D(T << i << endl;)
  D(T.unsetf(ios::uppercase);)
  D(T.setf(ios::oct, ios::basefield);)
  D(T << i << endl;)
  D(T.unsetf(ios::showbase);)
  D(T.setf(ios::dec, ios::basefield);)
  D(T.setf(ios::left, ios::adjustfield);)
  D(T.fill('0');)
  D(T << "fill char: " << T.fill() << endl;)
  D(T.width(10);)
  T << i << endl;
  D(T.setf(ios::right, ios::adjustfield);)
  D(T.width(10);)
  T << i << endl;
  D(T.setf(ios::internal, ios::adjustfield);)
  D(T.width(10);)
  T << i << endl;
  D(T << i << endl;) // Without width(10)

  D(T.unsetf(ios::showpos);)
  D(T.setf(ios::showpoint);)
  D(T << "prec = " << T.precision() << endl;)
  D(T.setf(ios::scientific, ios::floatfield);)
  D(T << endl << f << endl;)
  D(T.setf(ios::fixed, ios::floatfield);)
  D(T << f << endl;)
  D(T.setf(0, ios::floatfield);) // Automatic
  D(T << f << endl;)
  D(T.precision(20);)
  D(T << "prec = " << T.precision() << endl;)
  D(T << endl << f << endl;)
  D(T.setf(ios::scientific, ios::floatfield);)
  D(T << endl << f << endl;)
  D(T.setf(ios::fixed, ios::floatfield);)
  D(T << f << endl;)
  D(T.setf(0, ios::floatfield);) // Automatic
  D(T << f << endl;)

  D(T.width(10);)
  T << s << endl;
  D(T.width(40);)
  T << s << endl;
  D(T.setf(ios::left, ios::adjustfield);)
  D(T.width(40);)
  T << s << endl;

  D(T.unsetf(ios::showpoint);)
  D(T.unsetf(ios::unitbuf);)
//  D(T.unsetf(ios::stdio);) // SOMETHING MAY HAVE CHANGED
} ///:~