g++ -std=c++11 -Wall -I/opt/local/include -Iinclude src/main.cpp -o src/main.o
Undefined symbols for architecture x86_64:
  "RenderWindow::init(std::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, int)", referenced from:
      _main in ccLk05Ex.o
  "RenderWindow::show()", referenced from:
      _main in ccLk05Ex.o
  "RenderWindow::shutdown()", referenced from:
      _main in ccLk05Ex.o
  "RenderWindow::instance_", referenced from:
      RenderWindow::getInstance()       in ccLk05Ex.o
  "RenderWindow::RenderWindow()", referenced from:
      RenderWindow::getInstance()       in ccLk05Ex.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
make: *** [src/main.o] Error 1

The content of my main.cpp:

#include <iostream>

#include "renderwindow.h"

int main() {
    RenderWindow *renderWindow = RenderWindow::getInstance();
    renderWindow->init("OpenGL Framework", 640, 480);

    renderWindow->show();

    renderWindow->shutdown();
}

My OS is Mac OS X 10.9 and I'm using GLEW, GLFW and GLM.

Would you have any idea why I got those errors ?

Thanks in advance !