issue with using aliases: syntax error: missing ';' before '*'

Volapiik (41)
I have two classes unsorted.h and a child class Appointment.h. They Should take input in the form: 1/23/1999 Coffee

I want to use Appointment as ItemType but when I use typedef to do so, I get compilation errors. The below are a bunch of errors caused since it doesn't accept ItemType as an alias.

I know the issue has something to do with circular headers and the solution can be something using forward declarations. But I have tried a lot of different combinations and nothing seems to solve the compilation errors.


Errors:
```
Severity Code Description Project File Line Suppression State
Error C2143 syntax error: missing ';' before '*' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 20
Error C4430 missing type specifier - int assumed. Note: C++ does not support default-int Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 20
Error C2238 unexpected token(s) preceding ';' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 20
Error C2143 syntax error: missing ';' before '*' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 33
Error C4430 missing type specifier - int assumed. Note: C++ does not support default-int Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 33
Error C2334 unexpected token(s) preceding '{'; skipping apparent function body Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 33
Error C3867 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>::c_str': non-standard syntax; use '&' to create a pointer to member Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.cpp 28
Error C3867 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>::c_str': non-standard syntax; use '&' to create a pointer to member Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.cpp 29
Error C3867 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>::c_str': non-standard syntax; use '&' to create a pointer to member Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.cpp 30
Error C3867 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>::c_str': non-standard syntax; use '&' to create a pointer to member Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.cpp 34
Error C3867 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>::c_str': non-standard syntax; use '&' to create a pointer to member Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.cpp 35
Error C3867 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>::c_str': non-standard syntax; use '&' to create a pointer to member Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.cpp 36
Error C2039 'item_arr': is not a member of 'Appointment' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.cpp 59
Error C4430 missing type specifier - int assumed. Note: C++ does not support default-int Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.h 13
Error C2146 syntax error: missing ';' before identifier 'ItemType' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.h 13
Error C2371 'Appointment': redefinition; different basic types Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.h 14
Error C2504 'UnsortedType': base class undefined Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\appointment.h 15
Error C2143 syntax error: missing ';' before '*' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 20
Error C4430 missing type specifier - int assumed. Note: C++ does not support default-int Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 20
Error C2238 unexpected token(s) preceding ';' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 20
Error C2143 syntax error: missing ';' before '*' Lab3 c:\users\victornath\desktop\labs\datastruc\lab3\lab3\unsorted.h 33
```



Unsorted.h

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#ifndef LAB3_H
#define LAB3_H 
#include <iostream>
#include <string>
#include <cstdlib>
#include <iomanip>
#include "Appointment.h"
#include <vector>


using namespace std;
class Appointment; // forward declaration

class UnsortedType
{
    protected:
		int length = 0;
		int size;
	    //string *item_arr; //dynamic array of items
		ItemType *item_arr;
		//ItemType temp_obj;

	
    public:
		UnsortedType();
		UnsortedType(int num);
		UnsortedType(const UnsortedType& arg); // copy constructor
		UnsortedType& operator = (const UnsortedType& arg); // assignment operator
		~UnsortedType(); //destructor
		bool isFull();
		void PutItem(string s);
		int getLength() const { return length; };
	    ItemType* getitem_arr() const { return item_arr; };

};



#endif


Appointment.h
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#ifndef LAB3_H2
#define LAB3_H2
#include <iostream>
#include <string>
#include <cstdlib>
#include <iomanip>
#include "unsorted.h"
#include <vector>


using namespace std;

typedef Appointment ItemType;
class Appointment : public UnsortedType
{
	
	int year;
	int month;
	int day;
	string desc;
	string checker;

public:
	Appointment();
	Appointment(string s);
	friend istream& operator >> (istream& ins, Appointment& arg);
	friend ostream& operator << (ostream& out, const Appointment& arg);
	bool compare(const Appointment& arg1, const Appointment& arg2);
	int getYear() const { return year; };
	int getMonth() const { return month; };
	int getDay() const { return day; };
	string getDesc() const { return desc; };
	string getChecker() const { return checker; };
};

#endif
Repeater (3046)
Why is
#include "Appointment.h"
in Unsorted.h?

Dump this, it's doing nothing useful: typedef Appointment ItemType;


Change this
ItemType* getitem_arr() const { return item_arr; };
to
Appointment * getitem_arr() const { return item_arr; };


Your base class appears to directly refer to an inherited class. This is a design error. Base classes should not know or care about anything derived from them.
Last edited on
Volapiik (41)
The assignment description wants the appointment class to be aliased as ItemType. Also the reason I have the base class "knowing" about the child class is its needs to use ItemType objects to fill its array.

If I don't have Appointment.h in Unsorted.h, then I can't use ItemType in the unsorted files.
I tried fixing this by using a forward declaration and commenting out #include Appointment.h" so my unsorted.h file now looks like this:
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#ifndef LAB3_H
#define LAB3_H 
#include <iostream>
#include <string>
#include <cstdlib>
#include <iomanip>
//#include "Appointment.h"
#include <vector>


using namespace std;

class Appointment; // forward declaration

class UnsortedType
{
    protected:
		int length = 0;
		int size;
	    //string *item_arr; //dynamic array of items
		ItemType *item_arr;
		//ItemType temp_obj;

	
    public:
		UnsortedType();
		UnsortedType(int num);
		UnsortedType(const UnsortedType& arg); // copy constructor
		UnsortedType& operator = (const UnsortedType& arg); // assignment operator
		~UnsortedType(); //destructor
		bool isFull();
		void PutItem(string s);
		int getLength() const { return length; };
	    ItemType* getitem_arr() const { return item_arr; };

};



#endif
Last edited on
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