关于template的入门级问题
小弟初学GNUC++在按照书上的例子,如有有误。
class bifstream: public ifstream{
public:
bifstream(const char *fn):ifstream(fn, ios::in|ios::binary){};
void readBytes(void *,int cou);
template <class T>
bifstream &operator>>(T & d);
virtual ~bifstream();
};
bifstream::~bifstream()
{}
void bifstream::readBytes(void *p,int cou)
{
if(!p)return ;
if(cou<=0)return;
read((char*)p,cou);
}
template <class T>
bifstream &bifstream::operator>>(T & d)
{
readBytes(&d, sizeof(d));
return *this;
}
int main()
{
double d1,d2,d3 ;
d1 = 3.1415926;
bifstream bis("test.txt");
bis>>d1>>d2;//问题所在处 undefined referance .....
cout<<"d1"<<d1<<endl<<"d2"<<d2<<endl;
return 0;
}