Cunstom String Class

#include <iostream>


enum { STRLEN_MAX = 255 };

class String {
public:
    char s[STRLEN_MAX];

    String() {
        s[0] = 0;
    }

    String(const char *x) {
        s[0] = 0;
        int i = 1;
        while (*x && i < STRLEN_MAX) {
            s[i] = *x;
            ++x;
            ++i;
        }
        s[0] = i - 1;
    }

    char &operator [](int i) {
        if (i > STRLEN_MAX) {
            std::cerr << "Index out of range\n";
            return s[0];
        }
        return s[i];
    }

    char operator [](int i) const {
        if (i > s[0]) {
            std::cerr << "Index out of range\n";
            return s[0];
        }
        return s[i];
    }

    int get_len() const {
        return s[0];
    }

    String(const String &other) {
        for (int i = 0; i <= other.get_len(); ++i) {
            s[i] = other[i];
        }
    }

    String operator +(const String &other) {
        String res(*this);
        int i = 1;
        while (res[0] + 1 < STRLEN_MAX && i <= other.get_len()) {
            res[res[0] + 1] = other[i];
            ++i;
            ++res[0];
        }
        return res;
    }
};


std::ostream& operator <<(std::ostream &out, const String &S) {
    for (char i = 1; i <= S.get_len(); ++i) {
        out << S[i];
    }
    return out;
}

int main() {
    String X("abcdef");
    String Y("ababa");
    String T = X;
    std::cout << T << '\n';
}