如何在char的返回值中打印出字符串和int的数据成员？

#include <iostream>
#include <string>

char* printData(const std::string& str, int num) {
    char* result = new char[str.length() + sizeof(int) + 1];
    sprintf(result, "String: %s, Int: %d", str.c_str(), num);
    return result;
}

int main() {
    std::string str = "Hello";
    int num = 123;
    char* output = printData(str, num);
    std::cout << output << std::endl;
    delete[] output;
    return 0;
}