Why the struct is storing more bytes than its definition?

Question

In have this code:

#include <iostream>

using namespace std;

int main() {
    struct people {char name[50]; int tt; int gg;};
    
    struct people p1;
    cout << sizeof(p1);
    
    return 0;
}

the output is 60. Why?, I mean, the struct just would need to have 50+4+4=58 bytes. If we change the name[50] to name[20], we have the output: 28 as expected.

It is not contradicting that the memory used by the members of the struct are contiguous?.

Answer 1

For efficiency (primarily speed of execution), the compiler will align your int variables on a 4-byte boundary. The layout of your struct is therefore:

name     - 50 bytes
padding  - 2 bytes
tt       - 4 bytes
gg       - 4 bytes
------------------
total     60 bytes
------------------