title: Undefined Reference to class function issue
body: <p>I've scoured the internet and my own intellect to answer this basic question, however, much to my own dismay I've been unable to find a solution. I'm normally pretty good about multiple header files however I have hit a wall. The problem is a function that I've declared in a header and defined in its proper namespace in the source file. I'm developing on windows using Bloodshed.</p>
  
  <p>///////////////////////////////
      //  class Matrix4x3.h
      ///////////////////////////////</p>
  
  <pre><code>#ifndef _MATRIX4X3_H
  #define _MATRIX4X3_H
  
  class Matrix4x3{
      public:
  
          //set to identity
          void identity();
  
  };
  
  #endif
  </code></pre>
  
  <p>///////////////////////////////
  //  class Matrix4x3.cpp
  ///////////////////////////////</p>
  
  <pre><code>#include &lt;assert.h&gt;
  #include &lt;math.h&gt;
  #include "Matrix4x3.h"
  .
  .
  .
  void Matrix4x3::identity(){
      //calculations here...
  }
  </code></pre>
  
  <p>////////////// Main ////////////////</p>
  
  <pre><code>#include &lt;cstdlib&gt;
  #include &lt;iostream&gt;
  
  #include "../Matrix4x3.h"
  
  using namespace std;
  
  int main(int argc, char *argv[])
  {
      Matrix4x3 a;
  
      a.identity();
  
      cin.get();
      return EXIT_SUCCESS;
  }
  </code></pre>
  
  <p>I use Bloodshed, and it displays a list of class members and methods when I use the constructed object, however it tells me that the method dipicted above hasn't been referenced come time to compile. If anyone has a response I would be very appreciative. </p>