3. Template syntax for classes

Make this class declaration a template:

template < typename ValueT >
class Stack {
public:
    void push( ValueT item );
};

ValueT is the template parameter, standing in for the type.

When the user declares

    Stack< int > stack_i;

Template is instantiated for int, that is,
ValueT becomes int:

// Pseudocode:
template < typename ValueT=int >
class Stack {
public:
    void push( int item );
};