I am using eclipse to write c++ codes. When I try to write a header file and corresponding c++ file, it reminds me "member declaration not found" but I have no idea why this would happen since I declare it in my code...Okay, the codes are like:
LoadMedia.h
#pragma once
#include <string>
#include "LuaBridge.h"
class LoadMedia: public LuaParser
{
public:
LoadMedia();
virtual ~LoadMedia();
void loadScript(luabridge::lua_State* L, const std::string& scriptFilename);
};
And then, the LoadMedia.cpp
#include "LoadMedia.h"
#include "LuaBridge.h"
#include <string>
LoadMedia::LoadMedia(){}
LoadMedia::~LoadMedia(){}
void LoadMedia::loadScript(luabridge::lua_State* L, const std::string& scriptFilename)
{
using namespace luabridge;
if (luaL_dofile(L, scriptFilename.c_str()) != 0)
{
std::cout << "Error, cannot open the script!" << std::endl;
}
}
It reminds me that the loadScript is "member declaration not found"....Any idea why this is so and how should I correct it? Thanks for suggestion.
Related
I created a new project in c++ but i keep getting the same error
Main.cpp
#include <iostream>
#include <string.h>
#include "Computer.cpp"
#include "Computer.h"
using namespace std;
int main()
{
cout << "Hello World!" << endl;
return 0;
}
Computer.h
#ifndef COMPUTER_H_INCLUDED
#define COMPUTER_H_INCLUDED
#include <string>
class Computer
{
public:
std::string marca;
float prezzo;
bool acceso;
Computer();
void Accenditi();
void Spegniti();
void ImpostaMarca(std::string m);
void ImpostaPrezzo(float p);
};
#endif
Computer.cpp
#include "Computer.h"
Computer::Computer()
{
}
void Computer::Accenditi()
{
if(!acceso)
{
acceso = true;
}
else
{
std::cout << "Sono già acceso";
}
}
void Computer::Spegniti()
{
if(acceso)
{
acceso = false;
}
else
{
std::cout << "Sono già spento";
}
}
void Computer::ImpostaMarca(std::string m)
{
marca = m;
}
void Computer::ImpostaPrezzo(float p)
{
prezzo = p;
}
The Problem
i don't understand what's wrong with Computer.cpp, i keep getting "cout is not a member of std". I tryed to add "using namespace std" and i also tryed to add the library #include but i get a new file called "makefile.win". How can i fix this error ?
You need to include iostream header in your Computer.cpp file as such:
include <iostream>
and to make your life easier, you can also add:
using std::cout;
using std::endl;
right at the bottom of your include, that way you don't have to keep adding "std::cout" everytime, you can just use "cout"
Also want to add:
You can remove the include computer.cpp from your main.cpp and just leave the header. The C++ linker will automatically link your computer.h and computer.cpp together since .cpp includes the header, and your main includes the computer.h
Add # include <iostream> at the files that you use std::cout and std::cin.
What I have made is an fstreamExtension class that publically inherits fstream class.
fstreamExtension.h :
#include <fstream>
#include <string>
#include <vector>
#ifndef FSTREAMEXTENSION_H
#define FSTREAMEXTENSION_H
class fstreamExtension : public std::fstream
{
private:
std::string fileIdentifier;
public:
using std::fstream::fstream;
using std::fstream::open;
~fstreamExtension();
inline void fileName (std::string&);
inline bool exists ();
inline unsigned long long fileSize();
};
#endif
fstreamExtension.cpp :
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include "fstreamExtension.h"
inline void fstreamExtension::fileName (std::string& __fileIdentifier)
{
fileIdentifier = __fileIdentifier;
}
inline bool fstreamExtension::exists ()
{
if (FILE *file = fopen(fileIdentifier.c_str(), "r"))
{
fclose(file);
return true;
}
else
return false;
}
inline unsigned long long int fstreamExtension::fileSize()
{
if(exists())
{
std::ifstream tempStream(fileIdentifier.c_str(), std::ios::ate | std::ios::binary);
unsigned long long int __size = tempStream.tellg();
tempStream.close();
return __size;
}
else return 0;
}
fstreamExtension::~fstreamExtension()
{
std::fstream::close();
std::cout << "stream closed";
}
When this code is implemented in main file as :
#include <iostream>
#include <fstream>
#include "fstreamExtension.h"
int main()
{
string s = "QBFdata.txt";
fstreamExtension fs(s.c_str(), ios::in | ios::binary);
fs.fileName(s); //error
cout << fs.fileSize(); //error
}
There is a linker error when I call functions filename() and fileSize().
The codeblocks species the following error :
undefined reference to fstreamExtension::fileName(std::string&)
Thanks for your help, please suggest if any structure changes are required.
Remove inline from function declarations and definitions to fix the linker errors.
inline makes sense for functions defined in header files. For functions defined elsewhere inline makes them unavailable to other translation units, causing the linker error which you observe.
I have a compiling error in C++ using classes. I have worked with classes before and have never encountered this error. I have tried adding static before the method ImprtData but that only prompted more errors.
error: invalid use of non-static member function bank.ImprtData;
here is my .cpp
#include "componets.h"
User::User() {
std::cout << "loaded" << std::endl;
}
void User::ImprtData() {
std::cout << "loaded.\n";
}
and here is my .h
#include <sstream>
#include <fstream>
#include <vector>
#include <iostream>
#include <string>
class User {
public:
User();
void write();
void launch_main_menu();
void login();
void ImprtData();
private:
void deposit();
void withdrawl();
std::string account_name;
int account_pin;
float account_balance;
std::string account_user_name;
};
and finally my main
#include "componets.h"
int main() {
std::cout << "Welcome to Bank 111.\n";
User bank;
bank.ImprtData;
return 0;
}
This is essentially a simple typo. Replace
bank.ImprtData;
with
bank.ImprtData();
to call the function. The expression bank.ImprtData is confusing the compiler since it's interpreting it as the address of a function, and issues a diagnostic since the function is not static.
bank.ImprtData; should be bank.ImprtData();
I am trying to learn C++, however, the parameter to a method I have in my own class is misbehaving. When it uses a dataType of 'int', it works fine with no errors, but when I attempt to change it to a 'string' dataType, the program crashes with this error.
Error 1 error C2061: syntax error : identifier 'string' in temp.h ln
8 col 1
The classes I am using are as follows:
WORKING CODE
TesterClass.cpp // Entry Point
#include "stdafx.h"
#include "Temp.h"
int _tmain(int argc, _TCHAR* argv[])
{
Temp tmp;
tmp.doSomething(7);
return 0;
}
Temp.h
#pragma once
class Temp
{
public:
Temp();
void doSomething(int blah);
};
Temp.cpp
#include "stdafx.h"
#include "Temp.h"
#include <iostream>
#include <string>
using std::string;
Temp::Temp()
{
std::cout << "Entry" << std::endl;
string hi;
std::cin >> hi;
std::cout << hi << std::endl;
}
void Temp::doSomething(int blah)
{
std::cout << blah;
}
BROKEN CODE
Temp.h
#pragma once
class Temp
{
public:
Temp();
void doSomething(string blah);
};
Temp.cpp
#include "stdafx.h"
#include "Temp.h"
#include <iostream>
#include <string>
using std::string;
Temp::Temp()
{
std::cout << "Entry" << std::endl;
string hi;
std::cin >> hi;
std::cout << hi << std::endl;
}
void Temp::doSomething(string blah)
{
std::cout << blah;
}
When I adjust the parameter 'blah' to be a string, in both the .h and .cpp file, the problem occurs.
I have looked around, but none of the answers seem to solve my problem. I would greatly love help on this an I am out of ideas. I have tried reinstalling C++, messing with:
using namepace std;
using std::string;
std::string instead of string
etc.
If you know how to solve my problem I would love to hear from you. I am more than happy to provide more information.
C++ performs single-pass compilation, so std::string needs to be declared before you use it at all - including in the header file.
// Temp.h
#pragma once
#include <string>
class Temp
{
public:
Temp();
void doSomething(std::string blah);
};
I would encourage you to be specific in your header files when specifying classes like this, because you might easily come across another library that defines it's own string and then you would run into naming conflicts. Save the using import statements for your cpp files.
πάντα ῥεῖ had the write answer, thankyou!
They said to use std::string when needed, and to also #include <string> in the header file.
I have been stuck on this, my teacher doesn't even know what's going on. If someone could please help me that would be greatly appreciated.
I have declared item in the header file in the Line struct. However when calling on it in the Line::display() method, i get an error stating that the variable was not declared in the scope. I have showed my teacher and my peers and no one seems to know of the solutions.
Here is my .h:
//Line.h
#define MAX_CHARS 40
struct Line {
public:
bool set(int n, const char* str);
void display() const;
private:
char item[MAX_CHARS];
int no;
};
And here is my .cpp file.
// Line.cpp
#include "Line.h"
#include <iostream>
using namespace std;
#define MAX_CHARS 40
void Line::display() const {
cout << no << ' ' << item << endl;
}
Any help with this is awesome. Thanks in advance.
If this is your actual code, you're probably getting the header from somewhere else. Try:
#include "C:\\fullPathToHeader\\Line.h"
#include <iostream>
using namespace std;
void Line::display() const {
cout << no << ' ' << item << endl;
}
Also:
don't re-define MAX_CHARS in the cpp file.
use include guards for the header.
To make Line::display const implies you do not need instance variable data.
// Line.cpp
#include "Line.h"
#include <iostream>
using namespace std;
void Line::display()
{
cout << no << ' ' << Line::item << endl;
}