9.12 이니셜라이저리스트 연습문제

대입 과정에서 인덱스를 벗어났습니다.

아래 코드가 힌트가 되었으면 합니다.

첨부한 코드에서

cout << "before assigned : " << i << '\n';
mData[i++] = e;
cout << "after assigned : " << i << '\n';
cout << "mData[" << i << "]" << '\n';

그리고

cout << "mLength is " << mLength << endl;

위 두 코드를 추가했습니다.

$ cat test2.cc
#include <iostream>
#include<cassert>

using namespace std;
#include<initializer_list>

class IntArray
{
unsigned mLength = 0;
int *mData = nullptr;
public:
IntArray(unsigned length)
: mLength(length)
{
mData = new int[length];
}
~IntArray()
{
delete[]this->mData;
}
IntArray(const std::initializer_list<int> &list)
: IntArray(list.size())
{
int count = 0;
for ( auto &e : list )
{
mData[count] = e;
++count;
}
}

friend ostream &operator<<(ostream &os, IntArray &arr)
{
for ( unsigned i = 0; i < arr.mLength; ++i )
{
os << arr.mData[i] << " ";
}
os << endl;
return os;
}

//=operator
IntArray& operator=(const std::initializer_list<int> &array)
{
cout << "assignment operator" << endl;
delete[] mData;
mLength = array.size();
if(mData!=nullptr )
{
// mData = new int[mLength+1];
cout << "mLength is " << mLength << endl;
mData = new int[mLength];
int i {};
for ( auto &e : array )
{
cout << "before assigned : " << i << '\n';
mData[i++] = e;
cout << "after assigned : " << i << '\n';
cout << "mData[" << i << "]" << '\n';
}
}
else
{
mData = nullptr;
}
return *this;
}
};

int main()
{
IntArray intArray = {11,12,13,14,15,16,17,18,19,20};
intArray = {1,2,3,4,5,6,7,8,9,10};
cout << intArray << endl;
}

실행 결과는 다음과 같습니다.

$ ./a.out
assignment operator
mLength is 10
before assigned : 0
after assigned : 1
mData[1]
before assigned : 1
after assigned : 2
mData[2]
before assigned : 2
after assigned : 3
mData[3]
before assigned : 3
after assigned : 4
mData[4]
before assigned : 4
after assigned : 5
mData[5]
before assigned : 5
after assigned : 6
mData[6]
before assigned : 6
after assigned : 7
mData[7]
before assigned : 7
after assigned : 8
mData[8]
before assigned : 8
after assigned : 9
mData[9]
before assigned : 9
after assigned : 10
mData[10]
1 2 3 4 5 6 7 8 9 10