C++ 不识别 .h 声明

Question

我在 creature.h 中声明了以下函数(在 public 下):

void _hop();
void _turn(size_t way);
void _infect();
Point _facing();
bool _isEmpty();
bool _wall();
bool _same();

然后他们在 .cc 中的实现(为了简洁我删除了一堆代码):

void Creature::_hop(){
 CODE
}

Point Creature::_facing(){
  CODE
}

void Creature::_infect(){
  CODE
}

bool Creature::_isEmpty(){
 CODE
}

bool Creature::_wall(){
 CODE
}

bool Creature::_same(){
 CODE
}

但是在编译时我得到了这些错误:

creature.cc:25: error: no 'void Creature::_hop()' member function declared in class 'Creature'
creature.cc:54: error: no 'void Creature::_turn(size_t)' member function declared in class 'Creature'
creature.cc:88: error: no 'geometry::Point Creature::_facing()' member function declared in class 'Creature'
creature.cc:105: error: no 'void Creature::_infect()' member function declared in class 'Creature'
creature.cc:114: error: no 'bool Creature::_isEmpty()' member function declared in class 'Creature'
creature.cc:121: error: no 'bool Creature::_wall()' member function declared in class 'Creature'
creature.cc:127: error: no 'bool Creature::_same()' member function declared in class 'Creature'

许多其他功能都得到了很好的阅读，但这些功能却没有得到任何喜爱。 ??????

编辑:

不确定否决票，可能是因为你们假设我没有 a) 将它包含在生物类中或 b) #include "creature.h"。我两个都做了，只是没有在问题中包括它，因为我认为这是显而易见的。

编辑 2:您想要 .cc 和 .h？哦，亲爱的主。

怪物.H:

 #ifndef CREATURE
 #define CREATURE
 class Creature {
  public:
   // Constructor (note there is no need for a destructor.)
   Creature();
   Creature(Species *species,World *world,Point pt,Direction d);    

   // takeOneTurn executes lines of this creature's species program,
   // beginning on programLine and continuing until a HOP, LEFT, RIGHT, or 
   // INFECT is executed.
   void takeOneTurn();

   // getters and setters do the obvious things.
   Species *getSpecies();
   Direction getDirection();
   // use this to initialize and infect.  It also sets programLine to 1. 
   void setSpecies(Species * s); 
   void _hop();
   void _turn(size_t way);
   void _infect();
   Point _facing();
   bool _isEmpty();
   bool _wall();
   bool _same();

  private:
   Species *species;   // pointer to this creature's species
   World *world;       // a pointer to the world in which this 
                       // creature is located.
   Point loc;          // where in the world this creature is located
   Direction dir;      // current direction this creature is facing
   size_t programLine; // current program line  
 };

 #endif

生物.CC

 #include "creature.h"
 #include <cstdlib>

 Creature::Creature(Species *s, World *w,Point pt,Direction d){
   world = w;
   species = s;
   loc = pt;
   dir = d;
   programLine = 0;
 }


 Species* Creature::getSpecies(){
   return species;
 }

 Direction Creature::getDirection(){
   return dir;
 }

 void Creature::setSpecies(Species* s){
   species = s;
 }

 void Creature::_hop(){
   switch(dir){
   case NORTH:
     if(!world->getContents(Point(loc.col,loc.row+1))){
       world->setContents(loc, NULL);
       world->setContents(Point(loc.col,loc.row+1), this);
     }
     break;
   case SOUTH:
     if(!world->getContents(Point(loc.col,loc.row-1))){
       world->setContents(loc, NULL);
       world->setContents(Point(loc.col,loc.row-1), this);
     }
     break;
   case EAST:
     if(!world->getContents(Point(loc.col+1,loc.row))){
       world->setContents(loc, NULL);
       world->setContents(Point(loc.col+1,loc.row), this);
     }
     break;
   case WEST:
     if(!world->getContents(Point(loc.col-1,loc.row))){
       world->setContents(loc, NULL);
       world->setContents(Point(loc.col-1,loc.row), this);
     }
     break;
   }
 }

 void Creature::_turn(size_t way){
   if(way == 0){
     switch(dir){
     case NORTH:
       dir = WEST;
       return;
     case WEST:
       dir = SOUTH;
       return;
     case SOUTH:
       dir = EAST;
       return;
     case EAST:
       dir = NORTH;
       return;
     }
   } else {
     switch(dir){
     case NORTH:
       dir = EAST;
       return;
     case WEST:
       dir = NORTH;
       return;
     case SOUTH:
       dir = WEST;
       return;
     case EAST:
       dir = SOUTH;
       return;
     }
   }
 }

 Point Creature::_facing(){
   switch(dir){
   case NORTH:
     return Point(loc.col,loc.row+1);
     break;
   case WEST:
     return Point(loc.col-1,loc.row);
     break;
   case SOUTH:
     return Point(loc.col,loc.row-1);
     break;
   case EAST:
     return Point(loc.col+1,loc.row);
     break;
   }
 }

 void Creature::_infect(){
   Point facing = _facing();
   if(!world->inRange(facing))return;
   Creature* enemy = world->getContents(facing);
   if(!enemy) return;
   enemy->setSpecies(species);
   world->setContents(facing, enemy);
 }

 bool Creature::_isEmpty(){
   Point facing = _facing();
   if(!world->inRange(facing))return false;
   if(!world->getContents(facing)) return true;
   return false;
 }

 bool Creature::_wall(){
   Point facing = _facing();
   if(!world->inRange(facing))return true;
   return false;
 }

 bool Creature::_same(){
   Point facing = _facing();
   if(!world->inRange(facing))return true;
   if(!world->getContents(facing)) return false;
   Creature* enemy = world->getContents(facing);
   return (enemy->species == species);
 }

 bool _random(){
   int k =  random();
   return (k%2);
 }

 void Creature::takeOneTurn(){
   Instruction whatToDo = species->programStep(programLine);
   switch(whatToDo.op){
   case HOP:
     _hop();
     programLine++;
     break;
   case LEFT:
     _turn(0);
     programLine++;
     break;
   case RIGHT:
     _turn(1);
     programLine++;
     break;
   case INFECT:
     _infect();
     programLine++;
     break;
   case IFEMPTY:
     if(_isEmpty()){
       programLine = whatToDo.line;
       takeOneTurn();
     }
     break;
   case IFWALL:
     if(_wall()){
       programLine = whatToDo.line;
       takeOneTurn();
     }
     break;
   case IFSAME:
     if(_same()){
       programLine = whatToDo.line;
       takeOneTurn();
     }
     break;
   case GO:
     programLine = whatToDo.line;
     takeOneTurn();
     break;
   case IFRANDOM:
     if(_random()) programLine = whatToDo.line;
     else programLine++;
     takeOneTurn();
     break;
   }
 }

呸!

Answer 1

您所描述的应该没问题，因此我们不得不假设您的描述完全与现实不符。

具体而言，以下代码可以正常编译和运行。

pax$ cat creature.h
class Creature {
    public:
        void _hop();
};

pax$ cat creature.cc
#include <iostream>
#include "creature.h"

void Creature::_hop() {
    std::cout << "Hop\n";
}

int main (void) {
    Creature c;
    c._hop();
    return 0;
}

pax$ rm creature ; g++ -o creature creature.cc ; ./creature
Hop

由于该记录显示了您似乎在做什么，我的建议是发布您的实际代码以供分析，包括完整头文件和几乎完整的源文件(您可以保留 CODE 标记，因为它们不会影响此特定问题，但查看 include 语句等内容会很有用)。

最好的问题报告应该包括:

• 预期的行为。
• 实际行为。
• 展示错误行为的完整小程序。

---

根据您的代码更新(并假设它们已完成)，您遇到的问题是 size_t , Species , World , Point和 Direction在包含 creature.h 之前实际上并未定义在你的creature.cc文件。

这会导致创建 Creature类在第二个构造函数上失败，这样它就不会知道那个类。然后，当您尝试为所述类定义实际代码时，编译器(正确地)提示它不存在。

当我添加一个非常小的main到您的代码并尝试编译，我遇到了这些头文件问题:

In file included from creature.cc:1:
creature.h:5: error: expected `)' before '*' token
creature.h:13: error: ISO C++ forbids declaration of 'Species' with no type
creature.h:13: error: expected ';' before '*' token
creature.h:14: error: 'Direction' does not name a type
creature.h:16: error: 'Species' has not been declared
creature.h:18: error: 'size_t' has not been declared
creature.h:20: error: 'Point' does not name a type
creature.h:26: error: ISO C++ forbids declaration of 'Species' with no type
creature.h:26: error: expected ';' before '*' token
creature.h:27: error: ISO C++ forbids declaration of 'World' with no type
creature.h:27: error: expected ';' before '*' token
creature.h:29: error: 'Point' does not name a type
creature.h:30: error: 'Direction' does not name a type
creature.h:31: error: 'size_t' does not name a type

这是由那些非定义引起的。

然后我看到你描述的那种错误，例如:

creature.cc:129: error: 'world' was not declared in this scope
creature.cc:129: error: 'facing' was not declared in this scope
creature.cc:130: error: 'world' was not declared in this scope
creature.cc:130: error: 'facing' was not declared in this scope
creature.cc:131: error: 'world' was not declared in this scope
creature.cc:131: error: 'facing' was not declared in this scope
creature.cc:132: error: 'class Creature' has no member named 'species'
creature.cc:132: error: 'species' was not declared in this scope

(只是许多输出页面的示例)。

在包含 creature.h 之前，您需要确保包含了定义这些类型的头文件。 .理想情况下，creature.h会自己做这件事，而不是依赖使用它的任何东西。

size_t可以在 <cstring> 中找到，其他的需要自己找。例如，放置:

#include <cstring>
typedef int Species;
typedef int World;
typedef int Point;
typedef int Direction;

在你的头文件的顶部摆脱了所有这些错误 - 它引入了自 typedef 以来的一大堆其他错误陈述是错误的，但我只是在说明您需要在此处做什么。

找出那些其他东西的定义位置，并将它们与 <cstring> 一起包括在内, 在 creature.h 的顶部.