/********************************************************************* Filename: vect_ast.cpp Section: 11.1 Constructors and Destructors Compiler: Borland C++ Version 5.0 Summer 1996 C++ Distilled: Descriptions, Prescriptions and Style By Ira Pohl *********************************************************************/ //Implementation of a safe array type vect // Has assertions instead of check with message on // constructors and destructors #include#include //for exit #include //for assert class vect { public: //constructors and destructor explicit vect(int n = 10); //default constructor vect(const vect& v); //copy constructor vect(const int a[], int n); //initialization by array ~vect() { delete [] p; } int ub() const { return (size - 1); } //upper bound int& operator[](int i) const; //range checked vect& operator=(const vect& v); //not inherited vect operator+(const vect& v); friend ostream& operator <<(ostream& out, const vect& v); private: int* p; //base pointer int size; //number of elements }; //default constructor vect::vect(int n) : size(n) { assert(n > 0); p = new int[size]; assert (p != 0); //allocation error } //copy constructor vect::vect(const vect& v) : size(v.size) { p = new int[size]; assert (p != 0); for (int i = 0; i < size; ++i) p[i] = v.p[i]; } //constructor for initializing vect from an array vect::vect(const int a[], int n) : size(n) { assert(n > 0); p = new int[size]; assert (p != 0); for (int i = 0; i < size; ++i) p[i] = a[i]; } //overloaded subscript operator int& vect::operator [](int i) const { if (i < 0 || i > (size - 1) ) { cerr << "illegal vect index: " << i << endl; exit(1); } return (p[i]); } //overloaded output operator ostream& operator <<(ostream& out, const vect& v) { for (int i = 0; i <= (v.size-1); ++i) out << v.p[i] << '\t'; return (out << endl); } vect& vect::operator=(const vect& v) { if (this != &v) { //check for assign to self int s = (size < v.size) ? size : v.size; if (v.size != size) cerr << "copying different size arrays " << size << " and " << v.size << endl; for (int i = 0; i < s; ++i) p[i] = v.p[i]; } return (*this); } vect vect::operator+(const vect& v) { int s = (size < v.size) ? size : v.size; vect sum(s); if (v.size != size) cerr << "adding different size arrays " << size << " and " << v.size << endl; for (int i = 0; i < s; ++i) sum.p[i] = p[i] + v.p[i]; return sum; } void init_vect(vect& v, int start, int incr) { for (int i = 0; i <= v.ub(); ++i) { v[i] = start; start += incr; } } main() { int array[6] = { 5, 10, 15, 20, 25, 30 }; vect v1, v2(5); //use default constructor vect v3 (array, 5); //use construct and init from 1st 5 elements array vect v4 (v3); //use copy constructor init_vect(v1, 1, 1); cout << "\nvector v1 is " << v1; init_vect(v2, 0, 2); cout << "\nvector v2 is " << v2; cout << "\nvector v3 is " << v3; cout << "\nvector v4 is " << v4; v4 = v3 + v2; //test overloaded operator = + cout << "\nvector v4 is " << v4; }