LNK2019 error for no reason!

[tdm3732]

HI
This is my header file

 #ifndef _grid_h
#define _grid_h

template<typename T>
class grid{

private:
	T** main;
	int sizev;

public:

	grid();

	grid(int col, int row);

	~grid();

	void setDimensions(int col, int row);

	void set(int col, int row, T ob);

	T get(int col, int row);

	int size();
};


#endif 

and here is the interface

#include"grid.h"

template <typename T>
grid<T>::grid(){}

template<typename T>
grid<T>::grid(int col, int row){	
	setDimensions(col, row);
	sizev=col*row;
}

template<typename T>
grid<T>::~grid(){	
	delete[][] main;
}

template<typename T>
void grid<T>::setDimensions(int col, int row){
	main = new T*[col];
	for(int i =0;i<col;i++)
		main[i]=new T[row];
}

template<typename T>
void grid<T>::set(int col, int row, T ob){
	main[col][row] = ob;
}

template<typename T>
T grid<T>::get(int col, int row){
	return main[col][row];
}

template<typename T>
int grid<T>::size(){
	return sizev;
}

and here is the errors I get when I compile:

1>Source.obj : error LNK2019: unresolved external symbol "public: __thiscall grid<int>::grid<int>(int,int)" (??0?$grid@H@@QAE@HH@Z) referenced in function _main
1>Source.obj : error LNK2019: unresolved external symbol "public: __thiscall grid<int>::~grid<int>(void)" (??1?$grid@H@@QAE@XZ) referenced in function _main
1>C:\Users\yadi\documents\visual studio 2012\Projects\Grid\Debug\Grid.exe : fatal error LNK1120: 2 unresolved externals

Now we clearly see that I have defined both the constructor and destructor in the interface, why is it giving me this error?

[TheIdeasMan]

Hi,

All the template code must generally be in the header file. There is a work around, but it is not worth it IMO.

https://isocpp.org/wiki/faq/templates#templates-defn-vs-decl

HTH

[tdm3732]

Thank you. Thats how I made it work