/********************************************************************* Filename: vect_ovl.cpp Section: 11.5 Operator Overloading Compiler: Borland C++ Version 5.0 Summer 1996 C++ Distilled: Descriptions, Prescriptions and Style By Ira Pohl *********************************************************************/ //Implementation of a safe array type vect with exceptions // with exception handling and overloaded functions #include#include //for abort #include //for set_new_handler #include 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 friend vect operator+(const vect& v1, const vect& v2); 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) { if (n < 1) { strstream s; s << "Default constructor parameter is bad: " << n << ends; throw (s.str()); } //loop to force out of memory //for (int i = 0; i < 32000; ++i) { // cout << '\t' << i; // p = new int [32000]; //} p = new int[n]; //set new handler takes care of error } //copy constructor vect::vect(const vect& v) : size(v.size) { p = new int[size]; 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) { if (n <= 0) { strstream s; s << "\nArray init parameter is bad: " << n << ends; throw (s.str()); //give size error } p = new int[size]; for (int i = 0; i < size; ++i) p[i] = a[i]; } char* range_error(int i) { strstream s; s << "\nArray access parameter is bad: " << i << ends; return (s.str()); //give size error } //overloaded subscript operator int& vect::operator [](int i) const { if (i < 0 || i > (size - 1) ) throw range_error(i); return p[i]; } ostream& operator<<(ostream& out, const vect& v) { for (int i = 0; i <= (v.size-1); ++i) out << v.p[i] << '\t'; return (out << endl); } //overloaded assignment operator 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); } //overloaded binary + operator vect operator+(const vect& v1, const vect& v2) { int s = (v1.size < v2.size) ? v1.size : v2.size; vect sum(s); if (v1.size != v2.size) cerr << "adding different size arrays " << v1.size << " and " << v2.size << endl; for (int i = 0; i < s; ++i) sum.p[i] = v1.p[i] + v2.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; } } //simple memory error routine which aborts void Out_Of_Memory() { cerr << "\nFREE STORE EXHAUSTED\n"; abort(); } main() { try { 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 set_new_handler(Out_Of_Memory); cout << v3[20]; //force index error // vect v5(-5); //force size error // vect v6(array, -3) //force array init error 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; v4 = v1 + v3; //force add differenct size arrays cout << "\nvector v4 is " << v4; } catch (const char* msg) //catch any errors thrown with msg { cerr << endl << msg << endl; abort(); } }