Elements switch places on compilation? [closed] - c++

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I've been running into this really odd bug where a element of my array will swap places with another. I can solve the issue by manually changing the elements before compiling but for ease of access I want to keep it the way it is. My goal was to compare bits and store the result in an array. There is no function I actively call after I call that function so it doesn't change the array itself. It does the exact same thing when I declare the array as constants.
Here's my array:
int myconsts[8][8] = {
{ 6, 10, 0, 9, 14, 6, 6, 7 }
};
My issue as that number 14 (myconsts[4]) and 7 (myconsts[7]) would randomly swap places. Here's how I compare bits in my function
std::array<std::array<int, 4>, 8> myfunct(int arr[][8]) {
std::array<std::array<int, 4>, 8> arr2;
int i = 0;
do {
std::bitset<4> num1(arr[0][i]);
std::bitset<4> num2(arr[1][i]);
std::bitset<4> num3(arr[2][i]);
int no;
int no2;
int no3;
for (int x = 0; x < 4; x++) {
int sum = 0;
std::cout << num1[x] << " Num: " << num1[0] << num1[1] << num1[2] << num1[3] << std::endl;
}
std::cout << " " << std::endl;
i++;
} while (i < 8);
//just testing the logic
arr2 = { 0 };
return arr2;
}
Output:
[0]
0 Num: 0110
1 Num : 0110
1 Num : 0110
0 Num : 0110
[1]
0 Num : 0101
1 Num : 0101
0 Num : 0101
1 Num : 0101
[2]
0 Num : 0000
0 Num : 0000
0 Num : 0000
0 Num : 0000
[3]
1 Num : 1001
0 Num : 1001
0 Num : 1001
1 Num : 1001
Here is where it swaps positions with the original element[7]!
[4]
0 Num : 0111
1 Num : 0111
1 Num : 0111
1 Num : 0111
[5]
0 Num : 0110
1 Num : 0110
1 Num : 0110
0 Num : 0110
[6]
0 Num : 0110
1 Num : 0110
1 Num : 0110
0 Num : 0110
[7]
1 Num : 1110
1 Num : 1110
1 Num : 1110
0 Num : 1110
It's elements[0..7], every space in between represents a new element. I'm not sure if it's the same on all compilers.

Answer 1

I do not see what you are describing.
Here is my annotations on your output:
0 Num : 0111 // This is 2 + 4 + 8 = 14
1 Num : 0111
1 Num : 0111
1 Num : 0111
0 Num : 0110 // This is 2 + 4 = 6
1 Num : 0110
1 Num : 0110
0 Num : 0110
0 Num : 0110 // This is 2 + 4 = 6
1 Num : 0110
1 Num : 0110
0 Num : 0110
1 Num : 1110 // This is 1 + 2 + 4 = 7
1 Num : 1110
1 Num : 1110
0 Num : 1110
It looks like you just dumped: ..., 14, 6, 6, 7 };
which are the final 4 elements of your array.
I'd say everything looks correct.
Perhaps you are reading your bits backwards on screen, since LSB (least significant bit) is typically put on the far right, and you've put it on the far left.
But your code is working fine.