#include <cstring>    //for the function strlen
#include <stdexcept>  //for class out_of_range
#include "mystring.h"
using namespace std;

mystring::mystring(const char *s)    //plain old constructor
	: n {strlen(s) + 1}, p {new char[n]}
{
	for (int i {0}; i < n; ++i) {
		p[i] = s[i];   //Copy the characters into the block of memory.
	}
}

mystring::mystring(const mystring& another)  //"copy" constructor
	: n {another.n}, p {new char[n]}
{
	for (int i {0}; i < n; ++i) {
		p[i] = another.p[i];
	}
}

mystring& mystring::operator=(const mystring& another)
{
	if (this != &another) {
		delete[] p;   //Destruct the old value of this object.
		n = another.n;
		p = new char[n];
		for (int i {0}; i < n; ++i) {
			p[i] = another.p[i];
		}
	}
	return *this;
}

char mystring::operator[](size_t i) const //member func of const mystring object
{
	if (i >= n) {
		throw out_of_range("mystring subscript too big");
	}
	return p[i];
}

char& mystring::operator[](size_t i)  //member func of non-const mystring object
{
	if (i >= n) {
		throw out_of_range("mystring subscript too big");
	}
	return p[i];
}