'class X' has no member 'Y'
<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>
