noisy.h

来自「很经典的书籍」· C头文件 代码 · 共 73 行

//: C07:Noisy.h
// A class to track various object activities
#ifndef NOISY_H
#define NOISY_H
#include <iostream>
using std::endl;

class Noisy {
  static long create, assign, copycons, destroy;
  long id;
public:
  Noisy() : id(create++) {
    std::cout << "d[" << id << "]" << std::endl;
  }
  Noisy(const Noisy& rv) : id(rv.id) {
    std::cout << "c[" << id << "]" << std::endl;
    copycons++;
  }
  Noisy& operator=(const Noisy& rv) {
    std::cout << "(" << id << ")=[" <<
      rv.id << "]" << std::endl;
    id = rv.id;
    assign++;
    return *this;
  }
  friend bool
  operator<(const Noisy& lv, const Noisy& rv) {
    return lv.id < rv.id;
  }
  friend bool
  operator==(const Noisy& lv, const Noisy& rv) {
    return lv.id == rv.id;
  }
  ~Noisy() {
    std::cout << "~[" << id << "]" << std::endl;
    destroy++;
  }
  friend std::ostream&
  operator<<(std::ostream& os, const Noisy& n) {
    return os << n.id;
  }
  friend class NoisyReport;
};

struct NoisyGen {
  Noisy operator()() { return Noisy(); }
};

// A Singleton. Will automatically report the
// statistics as the program terminates:
class NoisyReport {
  static NoisyReport nr;
  NoisyReport() {} // Private constructor
public:
  ~NoisyReport() {
    std::cout << "\n-------------------\n"
      << "Noisy creations: " << Noisy::create
      << "\nCopy-Constructions: "
      << Noisy::copycons
      << "\nAssignments: " << Noisy::assign
      << "\nDestructions: " << Noisy::destroy
      << std::endl;
  }
};

// Because of the following definitions, this file
// can only be used in simple test situations. Move
// them to a .cpp file for more complex programs:
long Noisy::create = 0, Noisy::assign = 0,
  Noisy::copycons = 0, Noisy::destroy = 0;
NoisyReport NoisyReport::nr;
#endif // NOISY_H ///:~