Why do private member variables behaved like protected in the same module when creating deriving class?

[Steven Schveighoffer]

On 11/1/18 4:47 PM, Patrick Schluter wrote:
> On Thursday, 1 November 2018 at 19:26:05 UTC, Steven Schveighoffer wrote:
>> On 11/1/18 2:46 PM, Patrick Schluter wrote:
>>> [...]
>>
>> My testing looks like it's the same:
>>
>> #include <stdio.h>
>> int main()
>> {
>>     int arr[5];
>>     int *ptr = arr + 1; // point at second element so we can do 
>> negative indexing legally
>>     int idx1 = 0;
>>     ptr[--idx1] = 5;
>>     printf("%d\n", arr[0]); // 5
>>     size_t idx2 = 0;
>>     ptr[--idx2] = 6;
>>     printf("%d\n", arr[0]); // 6
>>     return 0;
>> }
>>
> Compiled with -m64 ? On a 32 bit machine it makes indeed no difference 
> as the effective calculated address is in any case modulo 2^32-1
> (a + 2^32-1) % 2^32 == a-1
> 

amd64 system (Intel Mac)

I wouldn't be surprised if on other architectures, you get a bus error.

-Steve