即使使用 ifndef，C++ 重定义错误

Question

我有几个文件，我的错误很奇怪。我不知道这是否是问题的一部分，我使用 OpenGL/SDL 和 XCode，并使用 CMake 创建文件。

我有文件 Wall.hpp、Wall.cpp、Player.hpp、Player.cpp、controls.hpp、controls.cpp、main.cpp。

这里是文件包含的总结:

//播放器.hpp

#include <iostream>


class Player{
    public :
    Player();
    int getLifePoints();
    int getStaminaPoints();
    float getPosX();
    float getPosY();
    float getPosZ();

    void setPosX(float x);
    void setPosY(float y);
    void setPosZ(float z);

    void reducePoints(int damage);
    bool isHeroRunning();
    void changeHeroRun();
    bool isHeroDucking();
    void changeHeroDuck();


    private :
    int lifePoints;
    int staminaPoints;
    float posX;
    float posY;
    float posZ;
    bool isRunning;
    bool isDucking;

};

//播放器.cpp

#include "Player.hpp"
using namespace std;

Player::Player(){
    this->lifePoints = 100;
    this->posX = 0;
    this->posY = 0;
    this->posZ = 0;
}

int Player::getLifePoints(){
    return this->lifePoints;
}
int Player::getStaminaPoints(){
    return this->staminaPoints;
}

float Player::getPosX(){
    return this->posX;
};
float Player::getPosY(){
    return this->posY;
};
float Player::getPosZ(){
    return this->posZ;
};

void Player::setPosX(float x){
    this->posX=x;
};
void Player::setPosZ(float z){
    this->posZ=z;
};
void Player::setPosY(float y){
    this->posY=y;
};

void Player::reducePoints(int damage){
    this->lifePoints= lifePoints - damage;
}

int lifePoints;
float posX;
float posY;
float posZ;

bool Player::isHeroRunning(){
    return isRunning;
}

void Player::changeHeroRun(){
    this->isRunning=!this->isRunning;
}

bool Player::isHeroDucking(){
    return this->isDucking;
}
void Player::changeHeroDuck(){
    this->isDucking=!this->isDucking;
    if (isDucking){
        this->posZ=this->posZ/2;
    } else {
        this->posZ=this->posZ*2;
    }
}

//Wall.hpp

#ifndef _WALL_H
#define _WALL_H

#include <iostream>
#include <vector>
// Include GLEW
#include <GL/glew.h>

// Include GLFW
#include <GL/glfw.h>

// Include GLM
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

class Wall{
    public :
    Wall(GLfloat x1, GLfloat x2, GLfloat z1, GLfloat z2);
    //~Wall();
    GLfloat getX1();
    GLfloat getX2();
    GLfloat getY1();
    GLfloat getY2();
    GLfloat getZ1();
    GLfloat getZ2();
    int isInZone(GLfloat x, GLfloat y, GLfloat z);
    std::vector<GLfloat> add_wall (std::vector<GLfloat> walls);


private:
    GLfloat x1, x2, y1, y2, z1, z2;

};

#endif

//墙.cpp

#ifndef _WALL_C
#define _WALL_C

// Include GLEW
#include <GL/glew.h>

// Include GLFW
#include <GL/glfw.h>

// Include GLM
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include "Wall.hpp"
#include <vector>

Wall::Wall(GLfloat x1, GLfloat x2, GLfloat z1, GLfloat z2){
    this->x1=x1;
    this->x2=x2;
    this->y1=y_floor;
    this->y2=y_ceiling;
    this->z1=z1;
    this->z2=z2;
}

#endif

//控件.hpp

#ifndef _MACRO_CONTROLS_C
#define _MACRO_CONTROLS_C

#include <vector>

#include "Wall.hpp"
...
#endif

//控件.cpp

#ifndef _MACRO_CONTROLS_C
#define _MACRO_CONTROLS_C


// Include GLFW
#include <GL/glfw.h>

// Include GLM
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
using namespace glm;

#include <iostream>

#include "controls.hpp"

#include <unistd.h>

#define GetCurrentDir getcwd

#include "Wall.hpp"
...
#endif

// main.cpp

// Include standard headers
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <list>
#include <vector>
#include <time.h>
#include <typeinfo>

// Include GLEW
#include <GL/glew.h>

// Include GLFW
#include <GL/glfw.h>

// Include GLM
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
using namespace glm;

#include <unistd.h>
#define GetCurrentDir getcwd

#include <common/shader.hpp>
#include <common/texture.hpp>
#include <common/controls.hpp>
#include "Player.cpp"
#include "Turret.hpp"

#include "Wall.hpp"

在我将 #include "Wall.hpp"放入文件 controls.hpp 或/和 controls.cpp 之前，代码运行良好。我面临错误“重新定义 Wall”，并且在此之后“Gl.h included before glew.h”。

Answer 1

我认为问题在于您在 controls.cpp 中包含 header 的方式:

Wall.hpp -> 类 WALL 的定义

controls.hpp -> 包含 wall.hpp

controls.cpp -> 包含 wall.hpp 和 controls.hpp

所以基本上在 controls.cpp 中你包含了 WALL 类的定义符两次；这可能是您出错的原因。如果你只包含 controls.hpp，你应该摆脱错误