Array as primitive data members in c plus plus program?

Answer 1

C-style arrays can be used as data members, both as fixed-size arrays or as dynamic arrays. The following examples demonstrate how they could be used as one-dimensional data members.

class a {

private:

int b[10] {0}; // in-class initialisation (all elements zero).

public:

int& operator[] (unsigned index) {

if (index>=10) throw std::range_error();

return b[index]; }

};

class c {

public:

c (unsigned sz=10): size(sz), p (size?new int[size]:nullptr) {

memset (p, 0, size); }

c (const s& _s): size(_s.size), p (size?new int[size]:nullptr) {

if (size) memcpy (p, _s.p, size); }

c (s&& _s): size(_s.size), p (_s.p) { _s.p=nullptr; } // swap resources

c& operator= (const s& _s) {

if (p) delete [] p;

size = _s.size;

p = (size?new int[size]:nullptr);

if (size) memcpy (p, _s.p, size); }

c& operator= (s&& _s) {

size = _s.size;

p = _s.p;

_s.p=nullptr; } // swap resources

~c() { if (p) delete [] p; }

int& operator[] (unsigned index) {

if (index>=size) throw std::range_error();

return p[index]; }

private:

unsigned size {0};

int* p {nullptr};

};

A much simpler approach would be to use std::array<int> and std::vector<int> instead of primitive C-style arrays.