/tmp/ex2-0da88f.o: In function `glDraw()':
ex2.cpp:(.text+0x12c): undefined reference to `Circle::Circle(_Point, float, float, float, float)'
ex2.cpp:(.text+0x193): undefined reference to `rectangle::rectangle(_Point, _Point, float, float, float)'
ex2.cpp:(.text+0x1f0): undefined reference to `Circle::draw()'
ex2.cpp:(.text+0x23f): undefined reference to `rectangle::draw()'
ex2.cpp:(.text+0x24c): undefined reference to `Shape::~Shape()'
ex2.cpp:(.text+0x27a): undefined reference to `Shape::~Shape()'
ex2.cpp:(.text+0x309): undefined reference to `Shape::~Shape()'
ex2.cpp:(.text+0x337): undefined reference to `Shape::~Shape()'
/tmp/ex2-0da88f.o:(.data+0x18): undefined reference to `typeinfo for Circle'
/tmp/ex2-0da88f.o:(.data+0x48): undefined reference to `typeinfo for rectangle'
clang: error: linker command failed with exit code 1 (use -v to see invocation)