C++ 不允许指向不完整的类类型的指针
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Pointer to incomplete class type is not allowed
提问by Sharpless512
For some reason I cannot use functions attached to the object I want to use. I added a comment to the line that is not working. As an error I get "Error; pointer to incomplete class type is not allowed" Please help
出于某种原因，我无法使用附加到我想要使用的对象的函数。我在不起作用的行中添加了一条评论。作为错误，我收到“错误；不允许指向不完整类类型的指针”请帮助
This is code in dokter.ccp
这是 dokter.ccp 中的代码
int counter = 0;
for (list<Wielrenner*>::iterator it = wielrenners.begin(); it != wielrenners.end(); it++){
Wielrenner* wielrennerOB = *it;
cout << "\nID: " << counter;
cout << "List size: " << persons.size() << endl;
wielrennerOB->print(); // This is not working
counter++;
}
This is code in wielrenner.h
这是 wielrenner.h 中的代码
#ifndef WIELRENNER_H_
#define WIELRENNER_H_
//#include <fstream>
#include "persoon.h"
#include "Onderzoek.h"
class Wielrenner :
public Persoon
{
public:
Wielrenner(string, string, Adres, string, Datum, Datum, string, int, float, float, float,list<Onderzoek>* );
~Wielrenner(void);
int getLengte() const;
float getGewicht() const;
float getVo2max() const;
float getMaxVermogen() const;
list<Onderzoek> getOnderzoekenList();
void setLengte(int);
void setGewicht(float);
void setVo2max(float);
void setMaxVermogen(float);
void voegOnderzoekToeList(Onderzoek);
void showOnderzoeksList();
void setOnderzoeksLijst(list<Onderzoek>&);
void print();
void printFile(ofstream&);
private:
int lengte;
float gewicht;
float vo2max;
float maxVermogen;
list<Onderzoek> onderzoeken;
};
#endif /* WIELRENNER_H_ */
code in wielrenner.CCP
wielrenner.CCP 中的代码
using namespace std;
#include <string>
#include "Wielrenner.h"
/*
#include "Onderzoek.h"
*/
Wielrenner::Wielrenner(string voornaam, string achternaam, Adres adres, string telefoon, Datum datumInDienst, Datum geboorteDatum,
string persoonType, int lengte, float gewicht, float vo2max, float maxVermogen,list<Onderzoek>* onderzoeken)
: lengte(lengte),
gewicht(gewicht),
vo2max(vo2max),
maxVermogen(maxVermogen),
Persoon(voornaam, achternaam, adres, telefoon, datumInDienst, geboorteDatum, persoonType)
{
}
Wielrenner::~Wielrenner(void)
{
}
//setten van gegevens
void Wielrenner::setLengte(int newLengte){
lengte = newLengte;
}
void Wielrenner::setGewicht(float newGewicht){
gewicht = newGewicht;
}
void Wielrenner::setVo2max(float newVo2max){
vo2max = newVo2max;
}
void Wielrenner::setMaxVermogen(float newMaxVermogen){
maxVermogen = newMaxVermogen;
}
void Wielrenner::voegOnderzoekToeList(Onderzoek newOnderzoek){
onderzoeken.push_back(newOnderzoek);
}
void Wielrenner::showOnderzoeksList(){
int teller=0;
for (list<Onderzoek>::iterator it = onderzoeken.begin(); it != onderzoeken.end(); it++){
Onderzoek onderzoekOB = *it;
cout << teller << " - ";
onderzoekOB.print();
teller++;
}
}
void Wielrenner::setOnderzoeksLijst(list<Onderzoek>& newOnderzoeksLijst){
onderzoeken = newOnderzoeksLijst;
}
void Wielrenner::print(){
cout << "(" << persoonID << ") Persoon: " << endl;
cout << persoonType << endl;
cout << voornaam << " " << achternaam << endl;
adres.print();
cout << telefoon << endl;
cout << "Datum in dienst: ";
datumInDienst.print();
cout << "Geboortedatum: ";
geboorteDatum.print();
cout << "> Extra wielrenner gegevens: " << endl;
cout << "Lengte: " << lengte << endl;
cout << "Gewicht: " << gewicht << endl;
cout << "vo2max: " << vo2max << endl;
cout << "maxVermogen: " << maxVermogen << endl;
}
void Wielrenner::printFile(ofstream &myfile){
myfile << persoonID << "\n";
myfile << persoonType << "\n";
myfile << voornaam << " " << achternaam << "\n";
adres.printFile(myfile);
myfile << telefoon << "\n";
datumInDienst.printFile(myfile);
geboorteDatum.printFile(myfile);
myfile << lengte << "\n";
myfile << gewicht << "\n";
myfile << vo2max << "\n";
myfile << maxVermogen << "\n";
}
// returnen van gegevens
int Wielrenner::getLengte() const{
return lengte;
}
float Wielrenner::getGewicht() const{
return gewicht;
}
float Wielrenner::getVo2max() const{
return vo2max;
}
float Wielrenner::getMaxVermogen() const{
return maxVermogen;
}
list<Onderzoek> Wielrenner::getOnderzoekenList(){
return onderzoeken;
}
回答by KRyan
An "incomplete class" is one declared but not defined. E.g.
“不完整的类”是声明但未定义的类。例如
class Wielrenner;
as opposed to
与
class Wielrenner
{
/* class members */
};
You need to #include "wielrenner.h"in dokter.ccp
你需要#include "wielrenner.h"在dokter.ccp
回答by Bryan Wilcutt
One thing to check for...
一件事要检查...
If your class is defined as a typedef:
如果您的类被定义为 typedef：
typedef struct myclass { };
Then you try to refer to it as struct myclassanywhere else, you'll get Incomplete Type errors left and right. It's sometimes a mistake to forget the class/struct was typedef'ed. If that's the case, remove "struct" from:
然后您尝试将其引用为struct myclass其他任何地方，您会左右得到不完整的类型错误。忘记类/结构是 typedef 的有时是错误的。如果是这种情况，请从以下位置删除“struct”：
typedef struct mystruct {}...
struct mystruct *myvar = value;
Instead use...
而是使用...
mystruct *myvar = value;
Common mistake.
常见的错误。
回答by Jeff Weichers
You get this error when declaring a forward reference inside the wrong namespace thus declaring a new type without defining it. For example:
在错误的命名空间内声明前向引用从而声明新类型而不定义它时，您会收到此错误。例如：
namespace X
{
namespace Y
{
class A;
void func(A* a) { ... } // incomplete type here!
}
}
...but, in class A was defined like this:
...但是，在 A 类中定义如下：
namespace X
{
class A { ... };
}
Thus, A was defined as X::A, but I was using it as X::Y::A.
因此， A 被定义为X::A，但我将其用作X::Y::A。
The fix obviously is to move the forward reference to its proper place like so:
解决方法显然是将前向引用移动到其适当的位置，如下所示：
namespace X
{
class A;
namespace Y
{
void func(X::A* a) { ... } // Now accurately referencing the class`enter code here`
}
}
回答by zeroDivider
Check out if you are missing some import.
检查您是否缺少某些导入。
回答by Matthis Kohli
I came accross the same problem and solved it by checking my #includes. If you use QKeyEvent you have to make sure that you also include it.
我遇到了同样的问题并通过检查我的#includes 解决了它。如果你使用 QKeyEvent 你必须确保你也包含它。
I had a class like this and my error appeared when working with "event"in the .cpp file.
我有一个这样的类，在 .cpp 文件中使用“事件”时出现了我的错误。
myfile.h
我的文件.h
#include <QKeyEvent> // adding this import solved the problem.
class MyClass : public QWidget
{
Q_OBJECT
public:
MyClass(QWidget* parent = 0);
virtual ~QmitkHelpOverlay();
protected:
virtual void keyPressEvent(QKeyEvent* event);
};
