Question

我有两个c ++类，比如说：

class A{
//Stuff from class B
};

class B{
//Stuff from class A
};

我决定从实现中分离接口，所以我有A.h和B.h头文件。如何管理包含？ A.h需要包括B.h，反之亦然，但这给了我编译器错误。我该怎么办？

编辑：这些是标题。

Vertex.h

/*
 * Vertex.h
 *
 *  Created on: Jun 24, 2014
 *      Author: marco
 */

#ifndef VERTEX_H_
#define VERTEX_H_
#include <string>
#include <iostream>
#include <map>
#include "Edge.h"

namespace MarcoGraphs {

class Vertex {
private:
    //Variables
    std::string id;
    int soglia;
    double peso;
    bool visited,convinto;
    std::map<std::string, Edge*> archi;
    //Disabled operations
    Vertex(const Vertex& param);
    Vertex& operator=(const Vertex&);
    Vertex(Vertex&&);
    Vertex& operator=(Vertex&&);
public:
    Vertex(std::string id);
    ~Vertex();
    std::map<std::string, Edge*>::iterator begin();
    std::map<std::string, Edge*>::iterator end();
    bool operator==(const Vertex& param) const;
    bool operator<(const Vertex& param) const;
    std::string getId() const;
    int getDegree() const;
    void setSoglia(int soglia);
    int getSoglia() const;
    void setVisited(bool value);
    bool isVisited() const;
    void setConvinto(bool value);
    bool isConvinto() const;
    void setPeso(double peso);
    double getPeso() const;
    bool addEdge(Edge& param);
    bool removeEdge(Edge& param);
};

std::ostream& operator<<(std::ostream& out, const Vertex& a);

} /* namespace MarcoGraphs */

#endif /* VERTEX_H_ */

Edge.h

/*
 * Edge.h
 *
 *  Created on: 29/giu/2014
 *      Author: Marco
 */

#ifndef EDGE_H_
#define EDGE_H_
#include "Vertex.h"

namespace MarcoGraphs {

class Edge {
private:
    //Variables
    Vertex* side1;
    Vertex* side2;
    //Forbidden operations
    Edge(const Edge& e);
    Edge& operator=(const Edge& e);
    Edge(Edge&& e);
    Edge&& operator=(Edge& e);
public:
    Edge(const Vertex& v1, const Vertex& v2);
    Vertex& getSide1();
    Vertex& getSide2();
    Vertex& getOtherEnd(const Vertex& thisEnd);
    ~Edge();
};

std::ostream& operator<<(std::ostream& out, const Edge& a);

} /* namespace MarcoGraphs */

#endif /* EDGE_H_ */

错误如下：

In file included from ..\Vertex.h:13:0,
                 from ..\Graph.h:10,
                 from ..\Graph.cpp:8:
..\Edge.h:17:2: error: 'Vertex' does not name a type
  Vertex* side1;
  ^
..\Edge.h:18:2: error: 'Vertex' does not name a type
  Vertex* side2;
  ^
..\Edge.h:25:13: error: 'Vertex' does not name a type
  Edge(const Vertex& v1, const Vertex& v2);
             ^
..\Edge.h:25:21: error: ISO C++ forbids declaration of 'v1' with no type [-fpermissive]
  Edge(const Vertex& v1, const Vertex& v2);
                     ^
..\Edge.h:25:31: error: 'Vertex' does not name a type
  Edge(const Vertex& v1, const Vertex& v2);
                               ^
..\Edge.h:25:39: error: ISO C++ forbids declaration of 'v2' with no type [-fpermissive]
  Edge(const Vertex& v1, const Vertex& v2);
                                       ^
..\Edge.h:26:2: error: 'Vertex' does not name a type
  Vertex& getSide1();
  ^
..\Edge.h:27:2: error: 'Vertex' does not name a type
  Vertex& getSide2();
  ^
..\Edge.h:28:2: error: 'Vertex' does not name a type
  Vertex& getOtherEnd(const Vertex& thisEnd);

Answer 1

 // header A;
 class B;

 class A {
     B* b;
 };

 // header B
 class A;

 class B {
     A* a;
 };

你必须使用指针，否则编译器无法弄清楚A或B需要多少空间，因为为了计算A的大小，你必须计算B的大小，为此你需要计算大小A.又名递归

嵌套包括在c ++中

1 个答案: