c++之 构造重载函数调用不明确

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

class Student
{
public:
  int id;
  char name[50]; // Data field
  int age; // Data field
  Student();
  Student(int fid, char* fname, int fage);
  //void set(int, char*, int);
  //void print();
};
  Student::Student(int fid = 0, char* fname = "No Name", int fage = 0)
{
    id = fid;
    strcpy(name,fname);
    age = fage;
}
  Student::Student()
{
      id = 0;
      strcpy(name,"No Name");
      age = 0;
}
  
void set(Student &student, int pid = 0, char* pname = "No Name", int page = 0)
{
    student.id = pid;
    strcpy(student.name,pname);
    student.age = page;
}
void print(Student student)
{
    cout << student.name << " (" << student.id << ") " << "is " << student.age << " years old." << endl;
}


int main()
{
  
  Student std1, std2(123, "Larry Jordan", 18), std3(124);//对重载函数的调用不明确
  set(std1, 100, "Steven Gates", 61);
  print(std1);
  print(std2);
  print(std3);
  return 0;
}
请问这到底是为什么啊？谢谢各位！