#include?<iostream>
#include?"Coordinate.h"
using?namespace?std;
class?Line
{
public:
Line();
~Line();
private:
Coordinate?*m_coorA;
Coordinate?*m_coorB;
};


Line::Line()
{
m_coorA?=?new?Coordinate(1,2);
m_coorB?=?new?Coordinate(3,4);
}??
Line::~Line()
{
}
int?main(void)
{
Line?*p;
p?=?new?Line();
delete?p;
p=NULL;
}

Coordinate那2個文件是一樣的,可以直接通過編譯的.但是,在編譯Line.cpp的時候報錯.

系統1:

Undefined symbols for architecture x86_64:

"Coordinate::Coordinate(int, int)", referenced from:

? ? ? Line::Line() in Line-6b7c1a.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

[Finished in 0.4s with exit code 1]

系統2:

/tmp/cc2zKqau.o: In function `Line::Line()':

Line.cpp:(.text+0x2a): undefined reference to `Coordinate::Coordinate(int, int)'

Line.cpp:(.text+0x50): undefined reference to `Coordinate::Coordinate(int, int)'

collect2: error: ld returned 1 exit status