c++ - 桥接模式C++代码编译错误

Question

我正在尝试编译桥接模式 C++ 示例代码，如前所述 here

但是当我执行 g++ -o Bridge Bridge.C

时出现编译错误

程序:

#include <iostream>
#include <iomanip>
#include <string>

class TimeImp {
  public:
    TimeImp(int hr, int min) {
        hr_ = hr;
        min_ = min;
    }
    virtual void tell() {
        cout << "time is " << setw(2) << setfill(48) << hr_ << min_ << endl; //error
    }
  protected:
    int hr_, min_;
};

class CivilianTimeImp: public TimeImp {
  public:
    CivilianTimeImp(int hr, int min, int pm): TimeImp(hr, min) {
        if (pm)
          strcpy(whichM_, " PM");
        else
          strcpy(whichM_, " AM");
    }

    /* virtual */
    void tell() {
        cout << "time is " << hr_ << ":" << min_ << whichM_ << endl;
    }
  protected:
    char whichM_[4];
};

class ZuluTimeImp: public TimeImp {
  public:
    ZuluTimeImp(int hr, int min, int zone): TimeImp(hr, min) {
        if (zone == 5)
          strcpy(zone_, " Eastern Standard Time");
        else if (zone == 6)
          strcpy(zone_, " Central Standard Time");
    }

    /* virtual */
    void tell() {
        cout << "time is " << setw(2) << setfill(48) << hr_ << min_ << zone_ << endl; //error
    }
  protected:
    char zone_[30];
};

class Time {
  public:
    Time(){}
    Time(int hr, int min) {
        imp_ = new TimeImp(hr, min);
    }
    virtual void tell() {
        imp_->tell();
    }
  protected:
    TimeImp *imp_;
};

class CivilianTime: public Time {
  public:
    CivilianTime(int hr, int min, int pm) {
        imp_ = new CivilianTimeImp(hr, min, pm);
    }
};

class ZuluTime: public Time {
  public:
    ZuluTime(int hr, int min, int zone) {
        imp_ = new ZuluTimeImp(hr, min, zone);
    }
};

int main() {
  Time *times[3];
  times[0] = new Time(14, 30);
  times[1] = new CivilianTime(2, 30, 1);
  times[2] = new ZuluTime(14, 30, 6);
  for (int i = 0; i < 3; i++)
    times[i]->tell();
}

错误:

]# g++ -o Bridge Bridge.C Bridge.C: In member function ‘virtual void TimeImp::tell()’: Bridge.C:14: error: no match for ‘operator<<’ in ‘std::operator<< [with _CharT = char, _Traits = std::char_traits](((std::basic_ostream >&)((std::basic_ostream >)std::operator<< [with _Traits = std::char_traits](((std::basic_ostream >&)(& std::cout)), ((const char)"time is ")))), std::setw(2)) << std::setfill with _CharT = int’ /usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/ostream.tcc:67: note: candidates are: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>& ()(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits] /usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/ostream.tcc:78: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ios<_CharT, _Traits>& ()(std::basic_ios<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits] /usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/ostream.tcc:90: note: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits]

这是错误的一部分，它以相同的模式扩展。

我已经复制粘贴了相同的代码，分析了错误行但无法得到它。

有人可以告诉我哪里错了吗？

Answer 1

std::setfill takes a char ，您正在向它传递 int。

尝试:

cout << "time is " << setw(2) << setfill(' ') << hr_ << min_ << endl;