UART Frame Builder

#include <iostream>
#include <cstdint>
using namespace std;

// Define class Frame with:
// - uint8_t buffer[16]
// - int size
// - operator+=
// - operator[]
// - getSize()
class Frame {
private:
    uint8_t buffer[16];
    int size;

public:
    Frame() : size(0) {}

    Frame& operator+=(int x){
        if (size < 16) {
            this->buffer[size++] = x;
        }
        return *this;
    }

    int operator[](int idx){
        return buffer[idx];
    }

    int getSize() const {
        return size;
    }
};
int main() {
    int n;
    cin >> n;

    Frame frame;

    for (int i = 0; i < n; i++) {
        int b;
        cin >> b;
        frame += (uint8_t)b;
    }

    for (int i = 0; i < frame.getSize(); i++) {
        cout << (int)frame[i];
        if (i + 1 < frame.getSize()) {
            cout << " ";
        }
    }

    return 0;
}

Solving Approach