问C++迭代具有混合字符长度的utf-8字符串

EN

#include <iostream>
#include "utf8.h"

using namespace std;

int main() {    
    string text = "今天周五123";

    char* str = (char*)text.c_str();    // utf-8 string
    char* str_i = str;                  // string iterator
    char* end = str+strlen(str)+1;      // end iterator

    unsigned char symbol[5] = {0,0,0,0,0};

    cout << symbol << endl;

    do
    {
        uint32_t code = utf8::next(str_i, end); // get 32 bit code of a utf-8 symbol
        if (code == 0)
            continue;

        cout << "utf 32 code:" << code << endl;

        utf8::append(code, symbol); // initialize array `symbol`

        cout << symbol << endl;

    }
    while ( str_i < end );

    return 0;
}