Linking errors :

[Quarternions]

Errors:

1>map.obj : error LNK2005: "int __cdecl RandomUtil(int,int)" (?RandomUtil@@YAHHH@Z) already defined in main.obj
1>map.obj : error LNK2005: "int __cdecl Round(double)" (?Round@@YAHN@Z) already defined in main.obj
1>   Creating library C:\Users\Quincy\Documents\Visual Studio 2008\Projects\Test\Debug\Test.lib and object C:\Users\Quincy\Documents\Visual Studio 2008\Projects\Test\Debug\Test.exp
1>C:\Users\Quincy\Documents\Visual Studio 2008\Projects\Test\Debug\Test.exe : fatal error LNK1169: one or more multiply defined symbols found

Code :
[cpp]
//main.cpp
#include <iostream>
#include <time.h>
#include <string>
#include "map.hpp"

int main()
{
std::string Input;
int Height,Width,quit;
quit=1;
srand(time(NULL));

std::cout << "Map Generator !" << std::endl << std::endl;
std::cout << "Input the number height and lenght" << std::endl;
std::cout << "Height : ";
std::cin >> Height;
std::cout << std::endl << "Width : ";
std::cin >> Width;

Map map (Width, Height);

while(quit!=0)
{

}

return 1;
}

//map.cpp
#include "map.hpp"

Map::Map(int W, int H)
{
Width = W;
Height = H;
map = new (std::nothrow) int[Width*Height];

for (int n=0; n<Height; n++)
{
for (int m=0; m<Width; m++)
{
map[n*Width+m] = 0;
}
}
}
void Map::Randomize()
{
int HillPos [5];
int size = Width*Height;
int NumHills = Round(size/25);

for (int n=0; n<=NumHills; n++)
{
HillPos[n] = RandomUtil(0,size);
}
}

void Map::SetHeight(int x,int y,int height)
{
map[((y-1)*Width+x)-1] = height;
}

void Map::Showmap()
{
std::cout << std::endl;
for (int n=0; n<Height; n++)
{
for (int m=0; m<Width; m++)
{
std::cout << map[n*Width+m];
}
std::cout << std::endl;
}
std::cout << std::endl;
}

//map.hpp
#ifndef MAP
#define MAP

#include <iostream>
#include <new>
#include "utils.hpp"

class Map
{
private:
int Width,Height;
int * map;
public:
Map(int W,int H);
void SetHeight(int x,int y,int height);
void Randomize();
void Showmap();
};

#endif
[/cpp]

I had to type/paste this very quickly but can anyone find the problem ?

Thanks in advance

[r4nk_]

The problem is in your utils.hpp, im guessing you have functions (specifically randomUtil and round) in the header which arn't inlined.

[Deco Da Man]

Change the top of your map.hpp so that the includes are above the header-included-check (or whatever they are called), like this:
[cpp]
#include <iostream>
#include <new>
#include "utils.hpp"

#ifndef MAP
#define MAP
[/cpp]

Then make sure utils.hpp has the same sort of system.

[b]Edit:[/b] You should also use a different naming convention for your header-included-check definitions (e.g: MAP_HPP_INCLUDED) to prevent collisions.

[jA_cOp]

[QUOTE=Deco Da Man;18108938]Change the top of your map.hpp so that the includes are above the header-included-check (or whatever they are called), like this:
[cpp]#ifndef MAP
#define MAP

#include <iostream>
#include <new>
#include "utils.hpp"
[/cpp]

Then make sure utils.hpp has the same sort of system.

[b]Edit:[/b] You should also use a different naming convention for your header-included-check definitions (e.g: MAP_HPP_INCLUDED) to prevent collisions.[/QUOTE]

You're missing an #endif...

[Deco Da Man]

[QUOTE=jA_cOp;18109004]You're missing an #endif...[/QUOTE]

I was only quoting the top part of the file...

[b]Edit:[/b] Fuck, I had forgotten to make the change I was telling him to do...

[r4nk_]

What are you guys talking about, his include guards are completely fine (unless I'm blind). But yea they should be named a bit less ambiguously.

The problem is with his utils.hpp which either has non-inline functions in the header or no include guards.

[editline]05:48PM[/editline]

[QUOTE=Deco Da Man;18109108]I was only quoting the top part of the file...

[b]Edit:[/b] Fuck, I had forgotten to make the change I was telling him to do...[/QUOTE]

WOAH

That is the [B]incorrect[/B] way!

[jA_cOp]

[QUOTE=Deco Da Man;18109108]I was only quoting the top part of the file...[/QUOTE]

[QUOTE=Deco Da Man;18108938]Change the top of your map.hpp[/QUOTE]

Half the solution, basically?

[Deco Da Man]

[QUOTE=r4nk_;18109119]WOAH

That is the [B]incorrect[/B] way![/QUOTE]

It works fine for me.

I had the same error, until I changed my headers to how I stated above.

[r4nk_]

[QUOTE=Deco Da Man;18109168]It works fine for me.

I had the same error, until I changed my headers to how I stated above.[/QUOTE]

Way to avoid the real problem. Read my post if you want to know the real problem.

[Deco Da Man]

Please explain to me how making the functions in util.hpp inline will help.
I'm assuming you mean:
[cpp]
inline int SomeFunction() { whatever; }
[/cpp]

If you mean placing the function in a header guard, then we are actually saying the same thing:
[QUOTE=Deco Da Man;18108938]Then make sure utils.hpp has the same sort of system.[/QUOTE]

Except you have the wrong terminology.

[r4nk_]

[QUOTE=Deco Da Man;18109252]Please explain to me how making the functions in util.hpp inline will help.[/QUOTE]

Ok I will explain it. If you include the header in more than 1 other file, non-inlined functions will have [B]multiple definitions[/B]. Same goes for non-static, non-extern variables:

[cpp]
#ifndef FILE_H
#define FILE_H

int x;

#endif[/cpp]

Will cause multiple definitions of x, if you include the file more than once.

[QUOTE=Deco Da Man;18109252]
If you mean placing the function in a header guard, then we are actually saying the same thing:

Except you have the wrong terminology.[/QUOTE]

If you are refering to me saying "include" guard, they mean the exact same thing.

If you are refering to the way I used the include guards, you are using them incorrectly. This is the correct way:
[cpp]
#ifndef FILE_H
#define FILE_H

//INCLUDES HERE

//EOF
#endif
[/cpp]

[Deco Da Man]

main.cpp:
[cpp]
#include <iostream>
#include <util.hpp>
#include <thingy.hpp>

int main() {
std::cout << the_thingy() << std::endl;
std::cout << the_util_func() << std::endl;
return 0;
}
[/cpp]

thingy.hpp
[cpp]
#include <util.hpp>

#ifndef THINGY_HPP_INCLUDED
#define THINGY_HPP_INCLUDED

const char* the_thingy();

#endif // THINGY_HPP_INCLUDED
[/cpp]

thingy.cpp:
[cpp]
#include <thingy.hpp>

const char* the_thingy() {
return the_util_func();
}
[/cpp]

util.hpp:
[cpp]
#ifndef UTIL_HPP_INCLUDED
#define UTIL_HPP_INCLUDED

const char* the_util_func();

#endif // UTIL_HPP_INCLUDED
[/cpp]

util.cpp:
[cpp]
#include <util.hpp>

const char* the_util_func() {
return "Hello world!";
}
[/cpp]

[r4nk_]

[cpp]
#ifndef UTIL_HPP_INCLUDED
#define UTIL_HPP_INCLUDED

const char* the_util_func();

#endif // UTIL_HPP_INCLUDED
[/cpp]

:facepalm:

We are talking about THIS:

[cpp]
#ifndef UTIL_HPP_INCLUDED
#define UTIL_HPP_INCLUDED

const char* the_util_func()
{
return "Hello world!";
}
#endif // UTIL_HPP_INCLUDED
[/cpp]

[efeX]

deco stick to lua cause you fail at C++
thanks

[blankthemuffin]

He means non inlined functions defined in the header, not declared.

[efeX]

-snip-

[editline]03:56AM[/editline]

broke my automerge
fuck dat mufin

[Deco Da Man]

[QUOTE=r4nk_;18109410]
[cpp]
#ifndef UTIL_HPP_INCLUDED
#define UTIL_HPP_INCLUDED

const char* the_util_func()
{
return "Hello world!";
}
#endif // UTIL_HPP_INCLUDED
[/cpp][/QUOTE]

That's not inlining, that's declaring.

[b]Edit:[/b] After doing a bit of googling, I've found that inline doesn't just mean a keyword that can be used with functions to do a certain compiler optimisation. It can also mean declaring a function in a header.
I apologise for causing confusion.

[r4nk_]

[quote=deco da man;18109485]that's not inlining, that's declaring.

[b]edit:[/b] after doing a bit of googling, i've found that inline doesn't just mean a keyword that can be used with functions to do a certain compiler optimisation. It can also mean declaring a function in a header.
I apologise for causing confusion.[/quote]

NO SHIT ITS NOT INLINING

ITS DEFINING

ITS NOT EVEN JUST DECLARING

IN THE HEADER

THATS WHAT THIS WHOLE THREAD IS ABOUT

where have you been!?

[Deco Da Man]

[QUOTE=r4nk_;18108524]The problem is in your utils.hpp, im guessing you have functions (specifically randomUtil and round) in the header [b]which arn't inlined.[/b][/QUOTE]

Crazy man, you are.

[r4nk_]

Yeah what the fuck is wrong with that?

If it isn't an inline function there will be multiple definitions

[Jallen]

I have no idea what the hell is happening after reading through the thread.

All I have to say is define your functions in a cpp file and declare them in a header which is included by the cpp which defines it.
Problem solved.

Whats with all the inline crap?

[r4nk_]

[QUOTE=Jallen;18109540]I have no idea what the hell is happening after reading through the thread.

All I have to say is define your functions in a cpp file and declare them in a header which is included by the cpp which defines it.
Problem solved.

Whats with all the inline crap?[/QUOTE]

The OP is having a multiple definitions error

Defining functions which arn't inlined inside a header will create multiple definitions if the header is included more than once.

The header in question is a utility header he made, which leads me to believe he is writing the small functions inside the header, and has forgotten to mark them as inline.

/thread

[Deco Da Man]

I didn't know making a function inline fixed this.

Rate me dumb, several times over.

[Jallen]

[QUOTE=r4nk_;18109551]The OP is having a multiple definitions error

Defining functions which arn't inlined inside a header will create multiple definitions if the header is included more than once.

The header in question is a utility header he made, which leads me to believe he is writing the small functions inside the header, and has forgotten to mark them as inline.

/thread[/QUOTE]

Right, yeah.

[B]GOOD[/B]

#ifndef lewl_h
#define lewl_h

inline void rofl()
{
    cout<<"MUDDDDKIPZZZZ\n";
}

#endif

[B]BAD[/B]

#ifndef lewl_h
#define lewl_h

void rofl()
{
    cout<<"MUDDDDKIPZZZZ\n";
}

#endif

[B]GOOD[/B]

#ifndef lewl_h
#define lewl_h

void rofl();

#endif

#include "lewl.h"

void rofl()
{
    cout<<"MUDDDDKIPZZZZ\n";
}

[r4nk_]

[QUOTE=Deco Da Man;18109562]_r4nk.

By the usage of the word 'inline' by a vastly large portion of C++ coders (including the [url=http://www.parashift.com/c++-faq-lite/inline-functions.html]C++ FAQ Lite[/url]), I had to assume you meant:
[cpp]
inline int whatever() {
whatever;
}
[/cpp]

[b]Get your terminology right.[/b]

This is the exact same question I have.[/QUOTE]

Jesus christ

You are telling me to get my terminology right:
[QUOTE=Deco Da Man;18109485]That's not inlining, that's declaring.

[b]Edit:[/b] After doing a bit of googling, I've found that inline doesn't just mean a keyword that can be used with functions to do a certain compiler optimisation. It can also mean declaring a function in a header.
I apologise for causing confusion.[/QUOTE]

That's DEFINING not DECLARING

And this:
[cpp]
inline int whatever() {
whatever;
}
[/cpp]

IS what im talking about

[editline]07:16PM[/editline]

Ok Deco I think I might see where you are getting confused.

When I made this post:

[QUOTE=r4nk_;18109410][cpp]
#ifndef UTIL_HPP_INCLUDED
#define UTIL_HPP_INCLUDED

const char* the_util_func();

#endif // UTIL_HPP_INCLUDED
[/cpp]

:facepalm:

We are talking about THIS:

[cpp]
#ifndef UTIL_HPP_INCLUDED
#define UTIL_HPP_INCLUDED

const char* the_util_func()
{
return "Hello world!";
}
#endif // UTIL_HPP_INCLUDED
[/cpp][/QUOTE]

I meant, the second example will NOT work because it is not an inlined function. I think you think that an inlined function is one thats simply put in a header with no need for the inlined keyword. Whereas I am actually talking about this being the solution:

[cpp]
#ifndef UTIL_HPP_INCLUDED
#define UTIL_HPP_INCLUDED

inline const char* the_util_func()
{
return "Hello world!";
}
#endif // UTIL_HPP_INCLUDED
[/cpp]

If that's not where the confusion is coming from, then I don't know what you are smoking but hook me up with some

[Deco Da Man]

Yep, that's it.

Sorry for causing confusion :/

[jA_cOp]

[QUOTE=Deco Da Man;18109626]Yep, that's it.

Sorry for causing confusion :/[/QUOTE]

[cpp]
/*Declaration*/
extern int a;
void func(void);
class A;

/*Definition*/
int a;
void func(){}
class A{};
[/cpp]

Not knowing the difference will cause you a lot of frustration in C and C++.

[Deco Da Man]

[QUOTE=jA_cOp;18109738][cpp]
/*Declaration*/
extern int a;
void func(void);
class A;

/*Definition*/
int a;
void func(){}
class A{};
[/cpp]

Not knowing the difference will cause you a lot of frustration in C and C++.[/QUOTE]

Thanks.
I always get the two confused.

Anyway, now that we've sorted out my idiocy, do you understand the problem, quincy18?