c++ 输出符的重载??
#include <iostream>
using namespace std;
//template<class T> ostream& operator<< ( ostream& os, const Array1D<T>& v);
template<class T>
class Array1D
{
friend ostream& operator<< ( ostream& os, const Array1D<T>& v );
public:
Array1D( int size = 0 );
T& operator[] ( int i ) const;
private:
int size;
T *element;
};
template<T> ostream& operator<< ( ostream& os, const Array1D<T>& v )
{
for(int i=0; i<size; ++i)
os << element[i] << ' ';
return os;
}
其他的函数都正确,加上重载的函数后就有错误,
编译器报的错误为:(我用的是dev c++ )
[Linker error] undefined reference to `operator<<(std::ostream&, Array1D<int> const&)'