Mutually dependent classes and inheritance - c++

I'm working on a little C++ WinAPI wrapper. I'd like to create my own window and append my own controls to it.
I created 2 classes : Window and Control.
The problem is that I struggle to deal with the multiple header files, because the class Control needs the class Window and vice versa. When I compile my code, I get many errors..
Here are my files :
globals.h :
// globals.h
// I need this file to define a few constants and to include the main headers needed by my classes
#ifndef GLOBALS_H
#define GLOBALS_H
#include <windows.h>
#include <iostream>
#include <vector>
#include "window.h"
#define SOME_GLOBAL_CONSTANT 1
#endif
window.h :
// window.h
#ifndef WINDOW_H
#define WINDOW_H
#include "globals.h"
#include "control.h"
class Window
{
public:
Window(RECT windowRect);
virtual ~Window();
void appendChild(Control* child);
private:
RECT m_windowRect;
Control m_staticBackground;
std::vector<Control*> m_children;
};
#endif
window.cpp :
// window.cpp
#include "window.h"
Window::Window(RECT windowRect) : m_windowRect(windowRect)
{
std::cout << SOME_GLOBAL_CONSTANT << std::endl;
}
Window::~Window()
{
m_children.clear();
}
void Window::appendChild(Control* child)
{
m_children.push_back(child);
}
control.h :
// control.h
#ifndef CONTROL_H
#define CONTROL_H
#include "globals.h"
class Control
{
public:
Control(Window* parentWindow);
virtual ~Control();
private:
RECT m_controlRect;
Window* m_parentWindow;
};
#endif
control.cpp :
// control.cpp
#include "control.h"
Control::Control(Window* parentWindow) : m_controlRect({}), m_parentWindow(parentWindow)
{
std::cout << SOME_GLOBAL_CONSTANT << std::endl;
}
Control::~Control()
{}
And finally, main.cpp :
#include "globals.h"
class MyCustomControl : public Control
{
public:
MyCustomControl(Window* parentWindow) : Control(parentWindow)
{}
~MyCustomControl()
{}
};
class MyWindow : public Window
{
public:
MyWindow(RECT windowRect) : Window(windowRect)
{
kid1 = new MyCustomControl(this);
appendChild(kid1);
}
~MyWindow()
{
delete kid1;
}
private:
MyCustomControl* kid1;
};
int main()
{
MyWindow appWindow;
std::cout << SOME_GLOBAL_CONSTANT << std::endl;
return 0;
}
Here are all the compilation errors I get :
1>------ Build started: Project: include, Configuration: Debug Win32 ------
1>window.cpp
1>d:\visual studio 2017\projects\include\include\control.h(9): error C2061: syntax error: identifier 'Window'
1>d:\visual studio 2017\projects\include\include\control.h(14): error C2143: syntax error: missing ';' before '*'
1>d:\visual studio 2017\projects\include\include\control.h(14): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>d:\visual studio 2017\projects\include\include\control.h(14): error C2238: unexpected token(s) preceding ';'
1>main.cpp
1>d:\visual studio 2017\projects\include\include\control.h(9): error C2061: syntax error: identifier 'Window'
1>d:\visual studio 2017\projects\include\include\control.h(14): error C2143: syntax error: missing ';' before '*'
1>d:\visual studio 2017\projects\include\include\control.h(14): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>d:\visual studio 2017\projects\include\include\control.h(14): error C2238: unexpected token(s) preceding ';'
1>d:\visual studio 2017\projects\include\include\main.cpp(8): error C2664: 'Control::Control(const Control &)': cannot convert argument 1 from 'Window *' to 'const Control &'
1>d:\visual studio 2017\projects\include\include\main.cpp(8): note: Reason: cannot convert from 'Window *' to 'const Control'
1>d:\visual studio 2017\projects\include\include\main.cpp(8): note: No constructor could take the source type, or constructor overload resolution was ambiguous
1>d:\visual studio 2017\projects\include\include\main.cpp(32): error C2512: 'MyWindow': no appropriate default constructor available
1>d:\visual studio 2017\projects\include\include\main.cpp(13): note: see declaration of 'MyWindow'
1>control.cpp
1>d:\visual studio 2017\projects\include\include\window.h(13): error C2061: syntax error: identifier 'Control'
1>d:\visual studio 2017\projects\include\include\window.h(17): error C3646: 'm_staticBackground': unknown override specifier
1>d:\visual studio 2017\projects\include\include\window.h(17): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>d:\visual studio 2017\projects\include\include\window.h(18): error C2065: 'Control': undeclared identifier
1>d:\visual studio 2017\projects\include\include\window.h(18): error C2059: syntax error: '>'
1>d:\visual studio 2017\projects\include\include\window.h(18): error C2976: 'std::vector': too few template arguments
1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.10.25017\include\vector(700): note: see declaration of 'std::vector'
1>Generating Code...
1>Done building project "include.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
Any help would be greatly appreciated.
Thank you in advance,
winapiwrapper.
Edit: I have also read this thread, but I couldn't solve my problem.

Welcome to programming. Strike down one error message and two shall take its place.
Well... Not really. What's happening is as you resolve one error, this reveals the errors that the precious errors were hiding.
First a PSA:
Don't write much code without compiling and testing. This way you have a smaller amount of code you need to check when something goes wrong. Start with a main function. Make sure it builds. Add the headers you need. Make sure it builds. Write a function for main to call. Make sure it builds. Repeat until program is finished. Trying to add too much all at once results in cascading storms of errors like you have experienced here.
Global include header files are usually a sucker bet. They often lead you into problems like the circular dependency you have here and make files include everything even when they don't have to. This can slow down build times.
Next, read the following link before continuing: Resolve header include circular dependencies
Now on with the answer:
window.h includes control.h. control .h includes window.h though global.h. This results in the Chicken and egg problem discussed in the above link. One of the headers is going to be included before the other and not be able to find the contents of the other file. Fortunately control.h only needs a reference to Window, not the whole thing, and this can be satisfied with a forward declaration and removing the global include file.
I'm not going to demonstrate cleaning this up. The process is well documented in the link.
This exposes hydra head number 2: Window contains Control m_staticBackground and does not explicitly initialize it. This results in the compiler hunting around for a default constructor for Control, something that does not exist.
Solution: Explicitly initialize m_staticBackground
Window::Window(RECT windowRect) : m_windowRect(windowRect),
m_staticBackground(this)
{
std::cout << SOME_GLOBAL_CONSTANT << std::endl;
}
BIG Mother Freaking note here: m_staticBackground(this) is dodgy as hell. this has not been fully constructed yet, so if you do more than simply store it in Control::Control (which is all you are currently doing) very bad, unpredictable things can happen. Do not use parentWindow or m_parentWindow inside the body of the Control constructor. If possible find a better, safer, way to do this. If not possible, document it with DO NOT USE messages to remind your future self or anyone else looking at the code not to use them.
Once this has been fixed you get to
MyWindow appWindow;
over in main. MyWindow's constructor requires a RECT you don't currently have a RECT to provide, so I'll stop here.

Move "window.h" from globals.h to controls.cpp. And put class Window; before class Controls { in controls.h. This is called forward declaration.
You even do not need window.h in controls.cpp, you can move it directly to your main.cpp.

Related

Cannot include std::thread header in wxWidgets application

I have the following code:
#include "wx\wx.h"
class BClient : public wxApp
{
virtual bool OnInit();
virtual int OnQuit();
};
IMPLEMENT_APP(BClient)
bool BClient::OnInit()
{
return true;
}
int BClient::OnQuit()
{
return 0;
}
As soon I try to add the line
#include <thread>
I receive this errors:
Error 10 error C2347: '__w64' : can not be used with type '__w64
unsigned __int64'
Error 12 error C2143: syntax error : missing ';' before ','
Error 13 error C2059: syntax error : ','
The errors refer to this file: c:\program files (x86)\microsoft visual studio 12.0\vc\include\concrt.h
So, for some reason, wxwidgets and std::thread doesn't mix together.
Can someone explain to me why this is happening and is there a workaround for this issue ?
Thanks.
Something is wrong with your MSVS installation. Here, adding #include <thread> line either before or after #include <wx/wx.h> one works without any problems.
Also, on a completely unrelated note, there is no OnQuit() in the base class, only OnExit().

Visual Studio 2012 Express compiler not linking header files together correctly

I am setting up some framework for a little 2D game. Right now, I just have a few classes, but I am immediately falling into compiler problems.
I have run this program with only the main function, so I can confirm that the Allegro (graphics library) library linking has worked.
I have put all my header files (.h) under the "Header Files" section in the Solution explorer and all my source (.cpp) in the "Source Files" section. I have only modified settings from default as according to this Allegro tutorial: http://wiki.allegro.cc/index.php?title=Windows,_Visual_Studio_2010_and_Allegro_5. It should not have affected anything in a destructive way.
I have several files, so I will list each one. I will skip some code to reduce size and redundancy. When I omit any code or do anything not verbatim, I will put a comment in the code saying so. (EDIT: I actually did not skip any code)
main.cpp
#include "common.h"
int main(int argc, char **argv)
{
ALLEGRO_DISPLAY *display = NULL;
World* world = new World(640, 480);
if(!al_init()) {
fprintf(stderr, "failed to initialize allegro!\n");
return -1;
}
display = al_create_display(640, 480);
if(!display) {
fprintf(stderr, "failed to create display!\n");
return -1;
}
al_clear_to_color(al_map_rgb(0,0,0));
world->draw(display);
al_flip_display();
al_rest(10.0);
al_destroy_display(display);
return 0;
}
common.h
#if !defined(COMMON_INC)
#define COMMON_INC
#include "World.h"
#include "Pane.h"
#include <stdio.h>
#include <allegro5/allegro.h>
#endif
World.h
#if !defined(WORLD_INC)
#define WORLD_INC
#include "common.h"
#include "Pane.h"
class World{
public:
World(int wp, int hp);
void draw(ALLEGRO_DISPLAY* display);
void update();
protected:
private:
Pane* panel;
int heightPix, widthPix;
};
#endif
World.cpp
#include "common.h"
World::World(int wp, int hp){
widthPix = wp;
heightPix = hp;
panel = new Pane(this, 10, 10, 300, 400);
return;
}
void World::draw(ALLEGRO_DISPLAY* display){
panel->draw(display);
return;
}
Pane.h
#if !defined(PANE_INC)
#define PANE_INC
#include "common.h"
class Pane{
public:
Pane(World* w, int xv, int yv, int wi, int he);
World* getWorld();
int getZ();
void draw(ALLEGRO_DISPLAY* display);
ALLEGRO_BITMAP* getBackground();
protected:
void setXY(int xv, int yv);
void setWidthHeight(int wi, int he);
void setZ(int zv);
void setBackground(ALLEGRO_BITMAP* ba);
private:
int z;
int x, y; //pixels
int width, height; //pixels
World* world;
ALLEGRO_BITMAP* background;
};
#endif
Pane.cpp
#include "common.h"
Pane::Pane(World* w, int xv, int yv, int wi, int he){
this->setWidthHeight(wi, he);
this->setXY(xv, yv);
this->world = w;
}
World* Pane::getWorld(){
return world;
}
void Pane::setXY(int xv, int yv){
x = xv;
y = yv;
return;
}
void Pane::setWidthHeight(int wi, int he){\
width = wi;
height = he;
return;
}
void Pane::setZ(int zv){
z = zv;
return;
}
void Pane::draw(ALLEGRO_DISPLAY* display){
if(background != NULL)
al_draw_bitmap(background, x, y, 0);
else{
background = al_create_bitmap(width, height);
al_set_target_bitmap(background);
al_clear_to_color(al_map_rgb(255, 0, 255));
al_set_target_bitmap(al_get_backbuffer(display));
al_draw_bitmap(background, x, y, 0);
}
return;
}
The compiler produces this error report upon building: (I called the game madscientist because it is supposed to be alchemy-themed)
1>------ Build started: Project: MadScientist, Configuration: Debug Win32 ------
1> main.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(8): error C2061: syntax error : identifier 'World'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): warning C4183: 'getWorld': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(11): error C2061: syntax error : identifier 'ALLEGRO_DISPLAY'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): warning C4183: 'getBackground': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(18): error C2061: syntax error : identifier 'ALLEGRO_BITMAP'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(24): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(24): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(10): error C2061: syntax error : identifier 'ALLEGRO_DISPLAY'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\main.cpp(22): error C2660: 'World::draw' : function does not take 1 arguments
1> World.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(8): error C2061: syntax error : identifier 'World'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): warning C4183: 'getWorld': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(11): error C2061: syntax error : identifier 'ALLEGRO_DISPLAY'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): warning C4183: 'getBackground': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(18): error C2061: syntax error : identifier 'ALLEGRO_BITMAP'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(24): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(24): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(10): error C2061: syntax error : identifier 'ALLEGRO_DISPLAY'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.cpp(6): error C2661: 'Pane::Pane' : no overloaded function takes 5 arguments
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.cpp(10): error C2511: 'void World::draw(ALLEGRO_DISPLAY *)' : overloaded member function not found in 'World'
1> c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(7) : see declaration of 'World'
1> Pane.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(8): error C2061: syntax error : identifier 'World'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): warning C4183: 'getWorld': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(11): error C2061: syntax error : identifier 'ALLEGRO_DISPLAY'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(12): warning C4183: 'getBackground': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(18): error C2061: syntax error : identifier 'ALLEGRO_BITMAP'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(24): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(24): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(10): error C2061: syntax error : identifier 'ALLEGRO_DISPLAY'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.cpp(3): error C2511: 'Pane::Pane(World *,int,int,int,int)' : overloaded member function not found in 'Pane'
1> c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(6) : see declaration of 'Pane'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.cpp(9): error C2556: 'World *Pane::getWorld(void)' : overloaded function differs only by return type from 'int *Pane::getWorld(void)'
1> c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9) : see declaration of 'Pane::getWorld'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.cpp(9): error C2371: 'Pane::getWorld' : redefinition; different basic types
1> c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9) : see declaration of 'Pane::getWorld'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.cpp(10): error C2065: 'world' : undeclared identifier
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.cpp(30): error C2511: 'void Pane::draw(ALLEGRO_DISPLAY *)' : overloaded member function not found in 'Pane'
1> c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(6) : see declaration of 'Pane'
1> Generating Code...
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
You have all of the info that I do. I will summarize it for you to save the trouble of looking through everything.
There are classes separated into header interfaces and source implementations
common.h is included by all files. It itself includes all of the class definitions in the other header files
When compiled, the compiler does not recognize classes defined in other header files as data types. Errors, as you would expect, cascade down.
The real-time error checker does not register any errors. When hovering over the word "World" when it is used as a datatype in Pane, for example, it recognizes the type perfectly. The real-time error checker is the feature that red underlines errors before compiler time.
This Visual Studio 2012 Express is new except for the modifications mentioned earlier. The project was created as an empty C++ project. Before many headers and sources were add, the main function compiled correctly.
Thank you for any responses. If you have any questions, please ask. The problems I have with Visual Studio always irk me.
EDITS:
My circular header logic is guarded by the header guards. I don't think this redundancy is a problem.
I tried removing all includes from my header files except for includes to Allegro libraries. This seemed to work better, but there are still weird problems. Why the act of including is causing these data types to error is still a mystery. Here is the new error log:
1>------ Build started: Project: MadScientist, Configuration: Debug Win32 ------
1> main.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1> World.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.cpp(6): error C2065: 'panel' : undeclared identifier
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.cpp(11): error C2065: 'panel' : undeclared identifier
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.cpp(11): error C2227: left of '->draw' must point to class/struct/union/generic type
1> type is ''unknown-type''
1> Pane.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1> Generating Code...
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
EDITS ROUND 2:
I switched my code around so the common.h only includes stdio and Allegro. All the header and source files include common.h and then any class's header file that they are using individually. Pane.cpp include Pane.h and common.h. World.h includes Pane.h and common.h.
Error log reads:
1>------ Build started: Project: MadScientist, Configuration: Debug Win32 ------
1> main.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C2061: syntax error : identifier 'World'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(10): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(10): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(10): warning C4183: 'getWorld': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1> World.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(9): error C2061: syntax error : identifier 'World'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(10): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(10): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(10): warning C4183: 'getWorld': missing return type; assumed to be a member function returning 'int'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\pane.h(25): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.cpp(7): error C2661: 'Pane::Pane' : no overloaded function takes 5 arguments
1> Pane.cpp
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C2143: syntax error : missing ';' before '*'
1>c:\users\ethoma\documents\visual studio 2012\projects\madscientist\madscientist\world.h(16): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1> Generating Code...
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
This is how I see my include order now:
main includes common
common defines COMMON_INC
common includes stdio and allegro
main includes World.h
World defines WORLD_INC
World includes common, which is blocked. But this should be okay because common is already included
World includes Pane
Pane defines PANE_INC
Pane includes common, which is blocked. But this should be okay because common is already included.
Pane includes World. This is blocked because main already included World. Shouldn't this be okay since World was already included. Why do I even have compiler guards if I need to include files many times over, once for each file that uses it?
EDITS ROUND 3:
I have learned a lot from the answers and comments here. It turns out that, according to Wikipedia, "circular dependencies are often introduced by inexperienced programmers who need to implement some kind of callback functionality." The mere fact that Pane uses World and World uses Pane is a design flaw. In Java, this was all fine for me. It was very easy; I thought that this was the best way to notify the entity that "possesses" an object of the object's actions.
It turns out that this is a bad design scheme. Objects should not have dependencies to their "possessors". Instead, I need to implement a observer system, where the Pane can tell the World that it has updated its state.
Reading wikipedia cleared up any questions that I had, so I now consider this question finished. Thanks to the contributors for putting up for a learning programmer.
You header files cannot be possibly linked correctly. You included your headers in circular fashion. Your header files include common.h, while common.h in turn includes other headers, like World.h and Pane.h.
This is not compilable by any compiler. You have to develop a hierarchy of headers, from low-level headers to high-level headers and make sure that higher-level headers include only lower-level headers. That way you will make sure you have no circular inclusions.
Anyway, why does your common.h include World.h and Pane.h? This looks like an obvious error. common.h is intended to be a low-level header. Let World.h and Pane.h include it, but don't include World.h and Pane.h into common.h.
Note, that header guards do not solve anything in this case. They simply make sure that the inclusion cycle will not get infinite. They break the cycle, but they don't help you to resolve circular dependencies between declarations, if such dependencies exist.
Look what happens in your case when processing main.cpp
main.cpp includes common.h
common.h defines COMMON_INC
common.h includes World.h
World.h defines WORLD_INC
World.h includes common.h. The whole common.h is skipped by include guards, because COMMON_INC got defined at step 2.
World.h includes Pane.h
Pane.h defines PANE_INC
Pane.h includes common.h. The whole common.h is skipped by include guards, because COMMON_INC got defined at step 2.
Pane.h referred to type World. Type World is unknown, since we haven't gotten to its definition in World.h yet. Error!
I think everything will compile even with the circular includes, if you make the following changes
In common.h you need to rearrange order of headers.
#include <allegro5/allegro.h>
#include "World.h"
#include "Pane.h"
#include <stdio.h>
In pane.h, after the #include common.h, add a forward declaration for class World
#include "common.h"
class World;
class Pane{
.....
I think this will make your errors disappear or atleast decrease them substantially.
My answer is based on the original code you put up, not on the Edit.

Error declaring vector in header file

I keep receiving a long string of errors when I try to declare a vector in the header. I've looked around for awhile, but can't find a solution.
Here are the errors:
1>Compiling... 1>game.cpp 1>c:\users\legacyblade\documents\visual
studio 2008\projects\fourswords\fourswords\input.h(38) : error C2143:
syntax error : missing ';' before '<'
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C2071:
'input::vector' : illegal storage class
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C4430: missing
type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C2238:
unexpected token(s) preceding ';' 1>main.cpp
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C2143: syntax
error : missing ';' before '<' 1>c:\users\legacyblade\documents\visual
studio 2008\projects\fourswords\fourswords\input.h(38) : error C2071:
'input::vector' : illegal storage class
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C4430: missing
type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C2238:
unexpected token(s) preceding ';' 1>input.cpp
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C2143: syntax
error : missing ';' before '<' 1>c:\users\legacyblade\documents\visual
studio 2008\projects\fourswords\fourswords\input.h(38) : error C2071:
'input::vector' : illegal storage class
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C4430: missing
type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\legacyblade\documents\visual studio
2008\projects\fourswords\fourswords\input.h(38) : error C2238:
unexpected token(s) preceding ';'
Here is the source code:
#include <vector>
#include <SFML/Graphics.hpp>
#ifndef _input_h
#define _input_h
class input
{
public:
input();
void update();
//----input keys----//
// Directions
bool upPress;
bool downPress;
bool leftPress;
bool rightPress;
// Actions
bool aPress;
bool bPress;
bool jumpPress;
bool shieldPress;
// Menu
bool startPress;
bool screenshotPress;
bool fullscreenPress;
//------------------//
private:
extern vector<sf::Keyboard::Key> keyBindings;
};
#endif
It gives me the same error with and without extern, and even if I change the type of thing inside the vector (even int).
Thank you so much for reading. It would be great if anyone could help. I need vectors to do what I'm wanting to do. Don't know why it's giving me such trouble. Any other type of variable in the same spot DOES NOT cause the error. Only vectors.
Just to add to what's been said, you need the namespace in the declaration because we usually don't want to bloat up header files with "using namespace std". So if you've seen vectors used elsewhere without std:: in front of it, the namespace was probably declared elsewhere.
You need to use the namespace for vector. Prefix vector with std::.
Also, extern on a class member semantically doesn't make any sense. Remove it.
std::vector<sf::Keyboard::Key> keyBindings;
extern vector<sf::Keyboard::Key> keyBindings;
should be
std::vector<sf::Keyboard::Key> keyBindings;

VS2008 C++ "interface" as a parameter name fails to compile

As the title says, I'm getting a compiler error in a VS2008 C++ program. I'm not sure how better to describe my problem than in code. The following compiles unless I uncomment the TEST line.
#include <windows.h>
#include <iostream>
using namespace std;
//#define TEST //<-- uncomment for error
#ifdef TEST
void test(void* interface)
{
return;
}
#endif
int main()
{
cout << "Hello World" << endl;
system("PAUSE");
return(0);
}
When uncommented I get the following errors:
1>main.cpp(7) : error C2332: 'struct' : missing tag name
1>main.cpp(7) : error C2144: syntax error : '<unnamed-tag>' should be preceded by ')'
1>main.cpp(7) : error C2144: syntax error : '<unnamed-tag>' should be preceded by ';'
1>main.cpp(7) : error C2059: syntax error : ')'
1>main.cpp(8) : warning C4094: untagged 'struct' declared no symbols
1>main.cpp(8) : error C2143: syntax error : missing ';' before '{'
1>main.cpp(8) : error C2447: '{' : missing function header (old-style formal list?)
This is unmanaged code, so I'm not sure what the issue with the word interface is. Is there any way to get this code to compile as is, or do I have to change every instance of the term interface to something else?
Thanks!
If your code needs to include Windows.h then you should avoid using the name interface as it's reserved for the use that the Windows SDK has reserved for it (essentially it's a synonym for the keyword struct). There are probably hacks to work around that problem (you could #undef interface after including the SDK headers), but you should probably avoid using that identifier.
The word interface is reserved by MSVC++, as it is a non-standard keyword added by Microsoft Compiler, which is used to define interface in MSVC++.
So use a different name for the parameter, something like this:
#ifdef TEST
void test(void* test_interface)
{
return;
}
#endif

Boost Unit Testing and Visual Studio 2005/Visual C++ and the BOOST_AUTO_TEST_SUITE(stringtest) namespace?

I'm reading this article on the Boost Unit Testing Framework.
However I'm having a bit of trouble with the first example, my guess is that they left something out (something that would be obvious to hardcore C++ coders) as IBM often does in their articles. Another possibility is that my Visual Studio 2005 C++ compiler is just too old for the example.
#include "stdafx.h"
#define BOOST_TEST_MODULE stringtest
#include <boost/test/unit_test.hpp>
//#include "mystring.h"
BOOST_AUTO_TEST_SUITE(stringtest) // name of the test suite is stringtest
BOOST_AUTO_TEST_CASE(test1)
{
/*
mystring s;
BOOST_CHECK(s.size() == 0);
*/
BOOST_CHECK(0 == 0);
}
BOOST_AUTO_TEST_CASE(test2)
{
/*
mystring s;
s.setbuffer("hello world");
BOOST_REQUIRE_EQUAL('h', s[0]); // basic test
*/
BOOST_CHECK(0 == 0);
}
BOOST_AUTO_TEST_SUITE_END()
To me the BOOST_AUTO_TEST_SUITE and BOOST_AUTO_TEST_CASE lines look a little suspect (especially since they don't have quotes around the arguments, and they are undeclared identifiers...but this probably means they are macros and I'm not certain I understand the concept or if that is available in VC++ 8.0)...
#ifdef _MYSTRING
#define _MYSTRING
class mystring {
char* buffer;
int length;
public:
void setbuffer(char* s) { buffer s = s; length = strlen(s); }
char& operator[ ] (const int index) { return buffer[index]; }
int size() {return length; }
}
#endif
Is there any reason why this code won't work?
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(7) : error C2065: 'stringtest' : undeclared identifier
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(9) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(9) : error C2146: syntax error : missing ';' before identifier 'BOOST_AUTO_TEST_CASE'
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(9) : error C2065: 'test1' : undeclared identifier
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(10) : error C2448: 'BOOST_AUTO_TEST_CASE' : function-style initializer appears to be a function definition
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(18) : error C2065: 'test2' : undeclared identifier
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(19) : error C2448: 'BOOST_AUTO_TEST_CASE' : function-style initializer appears to be a function definition
1>c:\users\andy\documents\visual studio 2005\projects\unittesttests\unittesttests\unittesttests.cpp(29) : fatal error C1004: unexpected end-of-file found
Looks correct to me. My Boost.Test code looks the same way. I'm running VS2008, but I know it works in 2005 as well.
Seems like your problem lies elsewhere.
If you use precompiled headers (and why do you do that in such a small test program?), shouldn't stdafx.h be included as the very first thing in the file?
And what is the first line for? You don't seem to use it, and _MYSTRING is a reserved name in C++ (everything that begins with underscore followed by a capital letter is off limits)