walrus.cpp

来自「C++编程思想第二版第一册答案」· C++ 代码 · 共 26 行

//: C18:Walrus.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Freezing a strstream
#include <iostream>
#include <strstream>
using namespace std;

int main() {
  ostrstream s;
  s << "'The time has come', the walrus said,";
  s << ends;
  cout << s.str() << endl; // String is frozen
  // s is frozen; destructor won't delete
  // the streambuf storage on the heap
  s.seekp(-1, ios::cur); // Back up before NULL
  s.rdbuf()->freeze(0); // Unfreeze it
  // Now destructor releases memory, and
  // you can add more characters (but you
  // better not use the previous str() value)
  s << " 'To speak of many things'" << ends;
  cout << s.rdbuf();
} ///:~