I have header file :
#ifndef VIP_TICKET_H
#define VIP_TICKET_H
#include "ticket.h"
class VIPTicket : public Ticket
{
public:
enum VIPType { FIRST_CLASS, FAST_LINE };
VIPType getTicketType() const;
private:
VIPType type;
};
#endif
and it's cpp file
#include "vipTicket.h"
VIPType VIPTicket::getTicketType() const
{
return type;
}
the error says " error C2143: syntax error : missing ';' before 'VIPTicket::getTicketType' "
this error is very confusing.. i guess it's not a ';' that is missing but probably something else wrong with the code that I can't put my finger on..
The problem is this definition
VIPType VIPTicket::getTicketType() const
{
...
}
When you define this function you have to remember that VIPType is not in the global scope, but in the scope of the VIPTicket class, so you have to explicitly mention the scope:
VIPTicket::VIPType VIPTicket::getTicketType() const
{
...
}
Related
I am still fairly new to C++, so sorry if the code is a bit amateurish, that might be the source of the problem.
I've spent some time searching this site and across the web. There are plenty of examples using enums (not enum class) and also of using enums and enums class outside of classes, but didn't really find anything useful for my particular scenario, see below. Of course, I may have seen the answer, but my C++ is not advanced enough yet to recognize it.
Basically I want to pass 2 "state" enums classes into a method, in a different class from the ones in which the enums classes are defined, and then change the state of the second enum class based on the value in the first enum class. These enum classes are defined inside a class which contains a pointer to the second class in which the method is defined. Class declarations are in header files and defined in separate .cpp files which include the relevant headers. See the detailed code and errors below.
Hoping someone can help me interpret the error messages at the end and figure out how to achieve this.
main.cpp
#include <iostream>
#include "firstfile.h"
int main() {
FirstFile firstobject;
firstobject.Function1();
}
Basically, I've got 2 enum classes inside following class.
firstfile.h
#include "secondfile.h"
class FirstFile
{
protected:
SecondFile secondobject;
public:
enum class enum1 {
Option1,
Option2
} enumIn = enum1::Option1;
enum class enum2 {
Option3,
Option4
} enumInOut = enum2::Option3;
// Methods
protected:
public:
void Function1();
};
firstfile.cpp
#include <iostream>
#include "firstfile.h"
void FirstFile::Function1()
{
std::cout << "Before the function call enumIn = Option 1 and enumInOut = Option3 " << std::endl;
secondobject.function2(enumIn, enumInOut);
if (enumInOut == enum2::Option4) {
std::cout << "After the function call enumInOut = Option 4" << std::endl;
}
else if (enumInOut == enum2::Option3) {
std::cout << "After the function call enumInOut = Option 3" << std::endl;
}
else {
std::cout << "enumInOut didn't match either Option 3 or Option 4" << std::endl;
}
}
The header file, where most of the errors occur.
secondfile.h
#include "firstfile.h"
class SecondFile
{
public:
void function2(const enum1& enumIn, enum2& enumInOut);
};
Finally, here is the method in class2 that is being called that should update enum2 based on the value of enum1.
secondfile.cpp
#include <iostream>
#include "firstfile.h"
#include "secondfile.h"
void SecondFile::function2(const enum1& enumIn, enum2& enumInOut)
{
if (enumIn == FirstFile::enum1::Option1) {
enumInOut = FirstFile::enum2::Option4;
}
}
The errors are:
firstfile.cpp
\secondfile.h(16, 28) : error C4430 : missing type specifier - int assumed.Note : C++ does not support default - int
\secondfile.h(16, 28) : error C2143 : syntax error : missing ',' before '&'
\firstfile.cpp(8, 42) : error C2660 : 'SecondFile::function2' : function does not take 2 arguments
\secondfile.h(16, 7) : message: see declaration of 'SecondFile::function2'
Main.cpp
\secondfile.h(16, 28) : error C4430 : missing type specifier - int assumed.Note : C++ does not support default - int
\secondfile.h(16, 28) : error C2143 : syntax error : missing ',' before '&'
secondfile.cpp
\secondfile.h(16, 28) : error C4430 : missing type specifier - int assumed.Note : C++ does not support default - int
\secondfile.h(16, 28) : error C2143 : syntax error : missing ',' before '&'
\secondfile.cpp(5, 39) : error C4430 : missing type specifier - int assumed.Note : C++ does not support default - int
\secondfile.cpp(5, 39) : error C2143 : syntax error : missing ',' before '&'
\secondfile.cpp(6, 6) : error C2065 : 'enumIn' : undeclared identifier
\secondfile.cpp(7, 3) : error C2065 : 'enumInOut' : undeclared identifier
Hope this all makes sense and look forward to any insights to help understand the cause of the errors and how I might be able to resolve them.
It's probably related to scope, but hoping to learn from this experience.
You have two issues:
You have circular dependencies, since you add the header of each classes to each other's header files. You can solve it via pointers members. Make the class member secondobject in the class FirstFile as a pointer, and provide a forward declaration in the header (i.e. in firstfile.h) for SecondFile.
Secondly, you need to specify the enum1 and enum2 from which class/ scope it is. You can use the using specifier for this, and enums will be available for the entire class SecondFile's scope.
That means, you need something like: (See Online)
firstfile.h
class SecondFile; // forward declaration
class FirstFile
{
protected:
SecondFile* secondobject{ nullptr }; // or smart pointers
public:
// ...enums and functions
};
firstfile.cpp
#include <iostream>
#include "secondfile.h"
void FirstFile::Function1()
{
// ...other code
if(secondobject)
secondobject->function2(enumIn, enumInOut);
// ^^^^^^^^^^^^
}
secondfile.h
#include "firstfile.h"
class SecondFile
{
public:
using enum1 = FirstFile::enum1; // specify from where the enums are
using enum2 = FirstFile::enum2;
void function2(const enum1& enumIn, enum2& enumInOut);
// ...other codes
};
secondfile.cpp
#include "secondfile.h"
void SecondFile::function2(const enum1& enumIn, enum2& enumInOut)
{
if (enumIn == enum1::Option1) {
enumInOut = enum2::Option4;
}
}
I am writing an algebra tree program. While compiling, I got a lot of errors. I do not know where the errors come from.
Here is my code:
//file: Term.h
#ifndef TERM
#define TERM
#include <sstream>
#include <string>
using namespace std;
class Term {
public:
Term() {}
virtual ~Term() {}
virtual string symbolicEval() = 0;
virtual double numericalEval(double X) = 0;
};
#endif
//file: UnaryOp.h
#ifndef UNARYOP
#define UNARYOP
#include "Term.h";
class UnaryOp: public Term{
protected:
Term* Child;
public:
UnaryOp(Term* l){Child = l;};
virtual ~UnaryOp(){delete Child;};
virtual string symbolicEval(){};
virtual double numericalEval(){};
};
#endif UNARYOP
//file:CCos.h
#ifndef COS_H
#define COS_H
#include "UnaryOp.h"
class Cos: public UnaryOp{
public:
Cos(Term * l):UnaryOp(l){};
virtual ~ Cos(){};
virtual string symbolicEval(){
ostringstream oss;
oss << "cos(x)" << endl;
return oss.str();
};
virtual double numericalEval(double X){
return cos(Child->numericalEval(X));
}
}
#endif COS_H
While compiling, I got the following errors:
1>c:\users\administrator\desktop\algebra\algebra\unaryop.h(3): warning C4067: unexpected tokens following preprocessor directive - expected a newline
1>c:\users\administrator\desktop\algebra\algebra\ccos.h(6): error C2236: unexpected 'class' 'Cos'. Did you forget a ';'?
1>c:\users\administrator\desktop\algebra\algebra\ccos.h(6): error C2143: syntax error : missing ';' before ':'
1>c:\users\administrator\desktop\algebra\algebra\ccos.h(6): error C2059: syntax error : ':'
1>c:\users\administrator\desktop\algebra\algebra\ccos.h(6): error C2059: syntax error : 'public'
1>c:\users\administrator\desktop\algebra\algebra\ccos.h(6): error C2143: syntax error : missing ';' before '{'
1>c:\users\administrator\desktop\algebra\algebra\ccos.h(6): error C2447: '{' : missing function header (old-style formal list?)
1>c:\users\administrator\desktop\algebra\algebra\algebra.cpp(29): error C2061: syntax error : identifier 'Cos'
Can someone give me a hint where am I wrong?
Start with replacing
#include "Term.h";
by
#include "Term.h"
(there may be more things wrong). And actually, the first error message exactly told you that the preprocessor was expecting a newline where you wrote a semicolon, so next time please read the error messages first.
Multiple things.
Why are you providing the definition for methods in header files?
//file:CCos.h
#ifndef COS_H
#define COS_H
#include "UnaryOp.h"
class Cos: public UnaryOp{
public:
Cos(Term * l):UnaryOp(l){};
virtual ~ Cos(){};
virtual string symbolicEval(){
ostringstream oss;
oss << "cos(x)" << endl;
return oss.str();
};
virtual double numericalEval(double X){
return cos(Child->numericalEval(X));
}
}
#endif COS_H
If you are using the "{}" after a method declaration in a ".H" file, would you please explain what does that mean?
How does a compiler understands it?
When do you use a colon? Is it after a method declaration or after a definition or for bothboth?
Are .h files compiled? why? why not?
If you could answer these, you have your answer. It is more of a homework. Request you to please post only relevant & only those questions, for which you need technical assistance.
you are missing closing brace of virtual string symbolicEval() function.
I've got a header in which my base problem is with the using keyword.
#ifndef SHAPEFACTORY_H__
#define SHAPEFACTORY_H__
#include <istream>
#include <map>
#include <string>
#include "shape.h"
/* thrown when a shape cannot be read from a stream */
template<class T>
class WrongFormatException { };
template<class T>
class ShapeFactory
{
public:
using createShapeFunction=Shape<T>*()(void);
static void registerFunction(const std::string &, const createShapeFunction *);
static Shape<T> *createShape(const std::string &);
static Shape<T> *createShape(std::istream &);
private:
std::map<std::string, createShapeFunction *> creationFunctions;
ShapeFactory();
static ShapeFactory<T> *getShapeFactory();
};
#endif
And I've got some errors which I can't resolve.
1>shapefactory.h(21): error C2873: 'createShapeFunction' : symbol cannot be used in a using-declaration
1>shapefactory.h(29) : see reference to class template instantiation 'ShapeFactory<T>' being compiled
1>shapefactory.h(21): error C2143: syntax error : missing ';' before '='
1>shapefactory.h(21): error C2238: unexpected token(s) preceding ';'
1>shapefactory.h(22): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>shapefactory.h(22): error C2143: syntax error : missing ',' before '*'
1>shapefactory.h(26): error C2065: 'createShapeFunction' : undeclared identifier
1>shapefactory.h(26): error C2059: syntax error : '>'
1>shapefactory.h(29): error C2143: syntax error : missing ';' before '}'
1>shapefactory.h(29): fatal error C1004: unexpected end-of-file found
Any idea would be great.
It seems that the compiler does not support the alias decladation. Substitute it for a typedef declaration. For example (at least the code is compiled)
#include <map>
#include <string>
template <typename T>
class Shape;
template<class T>
class ShapeFactory
{
public:
typedef Shape<T>* createShapeFunction(void);
static void registerFunction(const std::string &, const createShapeFunction *);
static Shape<T> *createShape(const std::string &);
static Shape<T> *createShape(std::istream &);
private:
std::map<std::string, createShapeFunction *> creationFunctions;
ShapeFactory();
static ShapeFactory<T> *getShapeFactory();
};
int main()
{
return 0;
}
I have a class "GameOverState" which has a private member
static const std::string s_gameOverID;
In GameOverState.cpp I am initialising as :
const std::string GameOverState::s_gameOverID = "GAMEOVER";
I am getting the following errors:
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
error C2440: 'initializing' : cannot convert from 'const char [9]' to 'int'
error C2377: 'std::string' : redefinition; typedef cannot be overloaded with any other symbol
error C2373: 's_gameOverID' : redefinition; different type modifiers
error C2143: syntax error : missing ';' before 'GameOverState::s_gameOverID'
I have a PlayState class/PauseState class which have the same implementation which are working fine. How do I fix this bug??
GameOverState.h
#pragma once
#include "GameState.h"
#include "PlayState.h"
#include "MenuState.h"
#include "PauseState.h"
#include "AnimatedGraphic.h"
#include <string>
class GameObject;
class GameOverState : public GameState
{
public:
virtual void update();
virtual void render();
virtual bool onEnter();
virtual bool onExit();
virtual std::string getStateID() const { return s_gameOverID; }
private:
static void s_gameOverToMain();
static void s_restartPlay();
static const std::string s_gameOverID;
std::vector<GameObject*> m_gameObjects;
}
GameOverState.cpp
#include "GameOverState.h"
const std::string GameOverState::s_gameOverID = "GAMEOVER";
void GameOverState::s_gameOverToMain()
{
TheGame::Instance()->getStateMachine()->changeState(new MenuState());
}
void GameOverState::s_restartPlay()
{
TheGame::Instance()->getStateMachine()->changeState(new PlayState());
}
bool GameOverState::onEnter()
{
if (!TheTextureManager::Instance()->load("assets/gameover.png", "gameovertext", TheGame::Instance()->getRenderer()))
{
return false;
}
if (!TheTextureManager::Instance()->load("assets/main.png", "mainbutton", TheGame::Instance()->getRenderer()))
{
return false;
}
if (!TheTextureManager::Instance()->load("assets/restart.png", "restartbutton", TheGame::Instance()->getRenderer()))
{
return false;
}
GameObject* gameOverText = new AnimatedGraphic(new LoaderParams(200, 100, 190, 30, "gameovertext"), 2);
GameObject* button1 = new MenuButton(new LoaderParams(200, 200, 200, 80, "mainbutton"), s_gameOverToMain);
GameObject* button2 = new MenuButton(new LoaderParams(200, 300, 200, 80, "restartbutton"), s_restartPlay);
m_gameObjects.push_back(gameOverText);
m_gameObjects.push_back(button1);
m_gameObjects.push_back(button2);
std::cout << "entering PauseState\n";
return true;
}
You're missing the semicolon after the definition of GameOverState.
The preprocessor runs before compilation and basically just copy pastes the content of the header in the source file, altough we can't see that. An error resulting from a broken header can thus be pretty misleading.
It's legal to have class definitions inside a variable definition and the position of specifiers (like static) is not limited to the beginning of a declaration, either (for example, int const static x = 0; is fine).
So, your code looks like this to the compiler:
class GameOverState {} static const std::string GameOverState::s_gameOverID = "GAMEOVER";
Hopefully the errors make more sense now.
As everyone else has said, you're probably missing the #include line in your header if your other two classes are working fine. It's presuming and expecting an int, so that seems the case.
Make sure #include<string> is in your header
I'm having some strange issues trying to initialize a static const member variable of a template class. All of my other static variables initialize fine but for some reason it doesn't like this one. I put together some sample code to test and it doesn't have the problem so I really don't know what's going on.
On top of this I'm also having issues defining functions that use typedefs declared inside of the template class with the same issue saying it can't find the type. This problem I have been able to reproduce though in the code below. I know one way to fix it is to define the function inside of the class, but the function is really large and I'm trying to keep it consistent with having all of the huge functions defined outside of the class to make the class definition easier to read. If that's my only option though then I guess I'll have to make an exception...
class tTestType
{
public:
tTestType(int32_t val) : fValue(val) { }
private:
int32_t fValue;
};
template<class T>
class tTestTemplate
{
public:
tTestTemplate() { }
private:
typedef std::vector<int32_t> tSomeVec;
tSomeVec mTestFunction() const;
static const tTestType kTestStatic;
};
// Should cause the following errors but I can't reproduce them for some reason:
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// error C2988: unrecognizable template declaration/definition
// error C2059: syntax error : 'constant'
template<class T>
const tTestType tTestTemplate<T>::kTestStatic(10);
// Causes the following errors:
// error C2143: syntax error : missing ';' before 'tTestTemplate<T>::mTestFunction'
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// fatal error C1903: unable to recover from previous error(s); stopping compilation
template<class T>
tTestTemplate<T>::tSomeVec tTestTemplate<T>::mTestFunction() const
{
tSomeVec result;
result.push_back(0);
return result;
}
Thanks to a coworker I've figured out a solution to both issues.
For the first issue, the static member variable, I've moved the definition to the CPP file and used a template specialization. The reason this doesn't break in the test code I posted is because the basic type (int, float, etc.) handle the problem, but if you use a more complex type, like a class, then it should cause the error. This solution isn't the best thing in the world to do, I know, but it's the only thing that works that is somewhat clean. If someone has a better solution please let me know:
template<>
const tTestType tTestTemplate<uint32_t>::kTestStatic(10);
For the second issue, the function using a type declared inside the class, I went with the solution I described in the initial post and just moved the function definition inside of the template class so now it looks like this:
template<class T>
class tTestTemplate
{
public:
tTestTemplate() { }
private:
typedef std::vector<int32_t> tSomeVec;
// Declaring the function inside the class to fix the compiler error.
tSomeVec mTestFunction() const
{
tSomeVec result;
result.push_back(0);
return result;
}
static const tTestType kTestStatic;
};
I made 2 changes in your code and its compiling fine.
class tTestType
{
public:
tTestType(int32_t val) : fValue(val) { }
private:
int32_t fValue;
};
typedef std::vector<int32_t> tSomeVec;
template<class T>
class tTestTemplate
{
public:
tTestTemplate() { }
private:
tSomeVec mTestFunction() const;
static const tTestType kTestStatic;
};
// Should cause the following errors but I can't reproduce them for some reason:
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// error C2988: unrecognizable template declaration/definition
// error C2059: syntax error : 'constant'
template<class T>
const tTestType tTestTemplate<T>::kTestStatic(10);
// Causes the following errors:
// error C2143: syntax error : missing ';' before 'tTestTemplate<T>::mTestFunction'
// error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
// fatal error C1903: unable to recover from previous error(s); stopping compilation
template<class T>
tSomeVec tTestTemplate<T>::mTestFunction() const
{
tSomeVec result;
result.push_back(0);
return result;
}