Question

Town.h

class Town;

Tailor.h

#include "Town.h"
class Bully;
#include "Bully.h"
class Tailor
{
  public:
    //LookAround is called only in randWalk
    void lookAround(Town & town, const short direction, const Bully bully[]);
    //THIS is the code inside randwalk that calls bully 
    if(!bully[0].punch(*this,town))

    void randWalk(Town & town, const Bully bully[]);
  private:
}

Bully.h

#include "Town.h"
class Tailor;
#include "Tailor.h"
class Bully
{
  public:
    bool punch(Tailor& tailor, Town & town);
  private:
}

的main.cpp

#include "Town.h"
#include "Tailor.h"
#include "Bully.h"

int main()
{
  const char PLAYER_NAME[] = "Milhouse";

  Bully bully_team[5];

  //create a town
  Town r(10,40,25);

  //create a Tailor player called PLAYER_NAME and place him at 2,3
  Tailor player(PLAYER_NAME);
  player.placeMe(r);

  //make the character move 12 times
  for(int i = 0; i < 100; i++)
  {
    player.randWalk(r, bully_team);
  }
  return 0;
}

问题是我需要在Player函数中访问Bully类型的数组，但是Bully需要类型Player才能运行。这个Bully数组需要在main中声明。我一直在尝试许多不同的转发类的方法，但我似乎无法让它工作。

In file included from Tailor.h:8:0,
                 from main.cpp:7:
Bully.h:43:17: error: 'MAX_NAME_LENGTH' was not declared in this scope
     char m_name[MAX_NAME_LENGTH];
                 ^
Bully.h: In function 'std::ostream& operator<<(std::ostream&, const Bully&)':
Bully.h:31:33: error: 'const class Bully' has no member named 'm_name'
       int length = strlen(bully.m_name);
                                 ^
Bully.h:35:23: error: 'const class Bully' has no member named 'm_name'
         cout << bully.m_name[i];
                       ^
In file included from Tailor.h:8:0,
                 from Tailor.cpp:1:
Bully.h:43:17: error: 'MAX_NAME_LENGTH' was not declared in this scope
     char m_name[MAX_NAME_LENGTH];
                 ^
Bully.h: In function 'std::ostream& operator<<(std::ostream&, const Bully&)':
Bully.h:31:33: error: 'const class Bully' has no member named 'm_name'
       int length = strlen(bully.m_name);
                                 ^
Bully.h:35:23: error: 'const class Bully' has no member named 'm_name'
         cout << bully.m_name[i];
                       ^
Tailor.cpp: In member function 'void Tailor::lookAround(Town&, short int, const Bully*)':
Tailor.cpp:70:34: error: passing 'const Bully' as 'this' argument discards qualifiers [-fpermissive]
     if(!bully[0].punch(*this,town))
                                  ^
In file included from Tailor.h:8:0,
                 from Tailor.cpp:1:
Bully.h:27:10: note:   in call to 'bool Bully::punch(Tailor&, Town&)'
     bool punch(Tailor& tailor, Town & town);
          ^

Answer 1

使用此订单：

声明Player和Bully
定义Player和Bully
定义Player和Bully以及main

2.中的订单可能很重要。 Player和Bully中只有一个可以依赖于另一个的定义，并且该依赖关系确定哪个必须在另一个之后定义。没有依赖关系的那个最多取决于另一个的声明。声明一个带有指向数组的指针的函数不需要定义指向的类型，因此Player显然不依赖于Bully的定义。

1.和3.中的顺序并不重要，如果您愿意，可以在单独的翻译单元（源文件）中定义每个功能。

我如何在类中使用不同类的数组？

1 个答案: