title: 'class X' has no member 'Y'
body: <p>This error is inexplicably occurring. Here is the code and output:</p>
  
  <p>timer.cpp:  </p>
  
  <pre><code>#include "timer.h"
  #include "SDL.h"
  #include "SDL_timer.h"
  
  void cTimer::recordCurrentTime()
  {
      this->previous_t = this->current_t;
      this->current_t = SDL_GetTicks();
  }</code></pre>
  
  <p>timer.h:  </p>
  
  <pre><code>#include "SDL.h"
  #include "SDL_timer.h"
  
  class cTimer
  {
  private:
      int previous_t;
      int current_t;
      float delta_time;
      float accumulated_time;
      int frame_counter;
  public:
      void recordCurrentTime();
      float getDelta();
      void incrementAccumulator();
      void decrementAccumulator();
      bool isAccumulatorReady();
      void incrementFrameCounter();
      void resetFrameCounter();
      int getFPS();
  };</code></pre>
  
  <p>Compiler errors:  </p>
  
  <pre>make
  g++ -Wall -I/usr/local/include/SDL -c timer.cpp
  timer.cpp: In member function ‘void cTimer::recordCurrentTime()’:
  timer.cpp:6: error: ‘class cTimer’ has no member named ‘previous_t’
  timer.cpp:6: error: ‘class cTimer’ has no member named ‘current_t’
  timer.cpp:7: error: ‘class cTimer’ has no member named ‘current_t’
  make: *** [timer.o] Error 1</pre>
  
  <p>Compiler errors after removing the #include "timer.h"</p>
  
  <pre>
  g++ -Wall -I/usr/local/include/SDL -c ctimer.cpp
  ctimer.cpp:4: error: ‘cTimer’ has not been declared
  ctimer.cpp: In function ‘void recordCurrentTime()’:
  ctimer.cpp:5: error: invalid use of ‘this’ in non-member function
  ctimer.cpp:5: error: invalid use of ‘this’ in non-member function
  ctimer.cpp:6: error: invalid use of ‘this’ in non-member function
  make: *** [ctimer.o] Error 1
  </pre>