classtemplatenontype.cpp

C++ sample code, for the book: C++ black book, including templates, exceptional handling.

#include <iostream>
using namespace std;

template <class T, int initial_value>
class Array
{
    T *ptr_to_array;
    int number;
public:
    explicit Array(int number_of_elements);
    Array(const Array & a);
    ~Array();
    T& operator= (const Array & a);
    T& operator[](int index) {return ptr_to_array[index];}
};

template <class T, int initial_value>
Array<T, initial_value>::Array(int number_of_elements)
{
    number = number_of_elements;
    ptr_to_array = new T[number];

    for(int loop_index = 0; loop_index < number; loop_index++) {
        ptr_to_array[loop_index] = initial_value;
    }   
}

template <class T, int initial_value>
Array<T, initial_value>::Array(const Array & a)
{
    number = a.number;
    T *ptr_to_array = new T[number];

    for(int loop_index = 0; loop_index < number; loop_index++) {
        ptr_to_array[loop_index] = a.ptr_to_array[loop_index];
    }   
}

template <class T, int initial_value>
T& Array<T, initial_value>::operator= (const Array & a)
{
    if(this == &a) return *this;
    delete[] ptr_to_array;

    number = a.number;
    T *ptr_to_array = new T[number];

    for(int loop_index = 0; loop_index < number; loop_index++) {
        ptr_to_array[loop_index] = a.ptr_to_array[loop_index];
    }   
    return *this;
}

template <class T, int initial_value>
Array<T, initial_value>::~Array()
{
    delete[] ptr_to_array;
}

int main()
{
    const int student_number = 5;
    Array<float, 50> scores(10);    

    cout << "Student number " << student_number << " scored " 
        << scores[student_number] << endl;

    return 0;
}