贴一下显示的错误信息
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x29): undefined reference to CSPoint::CSPoint(double, double)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x4d): undefined reference to
CSPoint::CSPoint(double, double)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x61): undefined reference to CSPoint::CSPoint(double, double)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x96): undefined reference to
operator>>(std::istream&, CSPoint&)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0xbb): undefined reference to operator<<(std::ostream&, CSPoint&)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0xdd): undefined reference to
operator<<(std::ostream&, CSPoint&)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x131): undefined reference to CSline::CSline(double, double, double, double)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x148): undefined reference to
CSline::CSline(CSPoint&, CSPoint&)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x166): undefined reference to CSline::display()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x188): undefined reference to
operator<<(std::ostream&, CSline&)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x19b): undefined reference to CSline::ifin(CSPoint&)'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x1f1): undefined reference to
CSline::~CSline()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x1fc): undefined reference to CSline::~CSline()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x208): undefined reference to
CSPoint::~CSPoint()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x214): undefined reference to CSPoint::~CSPoint()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x223): undefined reference to
CSPoint::~CSPoint()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x239): undefined reference to CSline::~CSline()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x249): undefined reference to
CSline::~CSline()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x25a): undefined reference to CSPoint::~CSPoint()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x26b): undefined reference to
CSPoint::~CSPoint()'
C:\Users\nmgxlms\AppData\Local\Temp\cc6b5Ils.o:main.cpp:(.text+0x27f): undefined reference to `CSPoint::~CSPoint()'