Implementing template member functions is somewhat different compared to the regular class member functions. Due to the way most compilers compile template based C++ code, the declarations and definitions of the class template member functions should all be in the same header file. In fact, for large projects where a template library is used in more than one location, the declarations and definitions need to be in the same header file. Consider the following.

//B.H
template <class t>
class b
{
public:
    b();
    ~b();
} ;

// B.CPP
#include "B.H"
template <class t>
b<t>::b()
{
}
template <class t>
b<t>::~b()
{
}

//MAIN.CPP
#include "B.H"
void main()
{
    b<int> bi;
    b<float> bf;
}

When compiling B.cpp, the compiler has both the declarations and the definitions available. At this point the compiler does not need to generate any definitions for template classes, since there are no instantiations. When the compiler compiles main.cpp, there are two instantiations: template class B<int> and B<float>. At this point the compiler has the declarations but no definitions!

While implementing class template member functions, the definitions are prefixed by the keyword template. Here is the complete implementation of class template Stack:

//stack.h
#pragma once
template <class T>
class Stack
{
public:
	Stack(int = 10) ; 
	~Stack() { delete [] stackPtr ; }
	int push(const T&); 
	int pop(T&) ;  // pop an element off the stack
	int isEmpty()const { return top == -1 ; } 
	int isFull() const { return top == size - 1 ; } 
private:
	int size ;  // Number of elements on Stack
	int top ;  
	T* stackPtr ;  
} ;

//constructor with the default size 10
template <class T>
Stack<T>::Stack(int s)
{
	size = s > 0 && s < 1000 ? s : 10 ;  
	top = -1 ;  // initialize stack
	stackPtr = new T[size] ; 
}
 // push an element onto the Stack 
template <class T>
int Stack<T>::push(const T& item)
{
	if (!isFull())
	{
		stackPtr[++top] = item ;
		return 1 ;  // push successful
	}
	return 0 ;  // push unsuccessful
}

// pop an element off the Stack
template <class T> 
int Stack<T>::pop(T& popValue) 
{
	if (!isEmpty())
	{
		popValue = stackPtr[top--] ;
		return 1 ;  // pop successful
	}
	return 0 ;  // pop unsuccessful
}