Problem compiling multiple files

[cth90]

I am having trouble linking these 3 files. I copied them directly from the book, but i cant seem to find the problem. I did some research and i found out something about having to put the function prototypes in main. I am using Dev c++ and these are the errors that im getting.

[Linker error] undefined reference to `rect_to_polar(rect)'
[Linker error] undefined reference to `show_polar(polar)'

Can someone please tell me what im doing wrong
coordin.h

#ifndef COORDIN_H_
#define COORDIN_H_

struct polar
{
       double distance;
       double angle;
};
struct rect
{
       double x;
       double y;
};

polar rect_to_polar(rect xypos);
void show_polar(polar dapos);

#endif 

file1.cpp

#include <iostream.h>
#include <conio.h>
#include "coordin.h"

using namespace std;
int main ()
{   
    rect rplace;
    polar pplace;
    
    cout << "Enter the x and y values: ";
    while (cin >> rplace.x >> rplace.y)
    {
          pplace = rect_to_polar(rplace);
          show_polar(pplace);
          cout << "Next two numbers (q to quit): ";
    }
    
    cout << "Bye!\n";
      
    getch();
    return 0;
}

file2.cpp

#include <iostream.h>
#include <conio.h>
#include <cmath>
#include "coordin.h"

polar rect_to_polar(rect xypos)
{
      using namespace std;
      polar answer;
      answer.distance = sqrt(xypos.x * xypos.x + xypos.y * xypos.y);
      answer.angle = atan2(xypos.y, xypos.x);
      return answer;
}

void show_polar(polar dapos)
{
     using namespace std;
     const double Rad_to_deg = 57.29577951;
     
     cout << "distance = " << dapos.distance;
     cout << ", angle = " << dapos.angle * Rad_to_deg;
     cout << " degrees\n";
}

[ModShop]

Are both .cpp files set to be compiled? Linker errors are caused by the compiler finding a function declaration, but not the definition (i.e. the .cpp file with the definition wasn't compiled).

[cth90]

I tried compiling each one separately but i kept getting errors for both cpp files. Is there a way to compile them both in Dev C++

[anonymous23323124]

Is there an option for "Build Project", "Build Solution", "Build All" or something similar.

PS: It seems that many people on this forum (probably including me) would recommend against use of Dev C++, as you can see here http://www.cplusplus.com/forum/articles/36896/
You should try Visual C++ Express or Code::Blocks :)

Hope this helps.

[cth90]

There is only one option that says rebuild all. I have tried this but i keep getting the same errors.

[ModShop]

There should be a button that looks like a box with an arrow pointing into it. Click on it and then add the other source file. You must have them in a project though, not just by themselves.

[cth90]

I tried putting them in a project but the same errors keep appearing. I downloaded code blocks and it still gives me the same errors. I guess it might be some error in my code or im not linking them properly.

[ModShop]

Your code looks fine, are both files set to compile?

[cth90]

wow im such an idiot, can someone please slap me lol. I just got them to work both on dev c++ and code blocks. I had to add each file into a project file, and then just compile them. Thanks to everyone who helped me.

[ModShop]

Everyone does stuff like that, especially me. lol