在用户定义的类中，Bool 作为函数 c++ 出现问题

嗨，我正在学习一门 c++ 课程，我们正在学习如何使用用户定义的类，但我的布尔值遇到了问题。到目前为止，我能达到的最远的距离是当我编译时出现错误

"没有匹配函数调用 StudRd：：ValidRd（） 注意：候选人是：bool StudRd：：ValidRd（StudRd&） const"

类，也是我第一次使用布尔函数。我已经讨论过这个问题，并在谷歌上搜索了几个小时的类似问题，但我觉得我离理解它并不近。

#include "stud.h"
int main()
{
  ifstream inFile;
  ofstream outFile;
  inFile.open("in.data");
  outFile.open("out.data");
  if(inFile.fail() || outFile.fail())//Checks the in and out files
{
    cout << "input file or output file opening failed" << endl;
}
  StudRd rd;                    //Declares an object of the class
  rd.DefaultRd();              //Default constructor
  outFile << "*~<Student Exam Report>~*" << endl;
  outFile << "Stud id" << setw(10) << "Exam 1" << setw(10) << "Exam 2" << setw(10) <<     "Exam 3" << setw(10) << "Avg" << endl;
rd.ReadRd(inFile, rd);
while(inFile){           //Loop until the file runs out of data
  rd.ValidRd(rd);                //Determines if data read is valid
  if(rd.ValidRd()){           //if statement is executed if bool returns valid
    rd.ValidCountRd(rd);
    rd.findAvg(rd);           //Function that figures out an average for the struct
    rd.MaxOfAllExams(rd);     //finds the highest valid exam
    rd.WriteRd(outFile, rd);  //Function that writes the struct to the outFile
  }
  else{
    rd.InvalidCountRd(rd);
    rd.WriteInvalidRd(outFile, rd);
  }
rd.ReadRd(inFile, rd);                //function that reads from the infile and assigns to a structure
 }
  rd.AvgOfAllExams(rd);                 //finds the average of all valid exams
  rd.WriteFooterRd(outFile, rd);        //Writes the footer containing max, avg, pass, fail, valid, invalid
  outFile << "*** END ***" << endl;
  return 0;
}

以下是类和函数实现

#include "stud.h"
void StudRd :: DefaultRd()
{
  id = -111;
  exam1 = -100;
  exam2 = -100;
  exam3 = -100;
  numValid = 0;
  numInvalid = 0;
  numPass = 0;
  numFail = 0;
}
bool StudRd :: ValidRd(StudRd& rd) const
{
  return(111 <= rd.id <= 999 &&
         0 <= rd.exam1 <= 100 &&
         0 <= rd.exam2 <= 100 &&
         0 <= rd.exam3 <= 100);
}
void StudRd :: ValidCountRd(StudRd& rd)
{
  rd.numValid++;
}
void StudRd :: InvalidCountRd(StudRd& rd)
{
  rd.numInvalid++;
}
void StudRd :: MaxOfAllExams(StudRd& rd)
{
    if(rd.examMax < rd.exam1){
      rd.examMax = rd.exam1;
}
    if(rd.examMax < rd.exam2){
      rd.examMax = rd.exam2;
    }
    if(rd.examMax < rd.exam3){
      rd.examMax = rd.exam3;
    }
}
void StudRd :: AvgOfAllExams(StudRd& rd)
{
  rd.avgOfAllExams = rd.examSum / rd.numValid;
}
void StudRd :: ReadRd(ifstream& inFile, StudRd& rd)
{
  inFile >> rd.id >> rd.exam1 >> rd.exam2 >> rd.exam3;
}
void StudRd :: WriteRd(ofstream& outFile, StudRd rd)
{
  inFile >> rd.id >> rd.exam1 >> rd.exam2 >> rd.exam3;
}
void StudRd :: WriteRd(ofstream& outFile, StudRd rd)
{
  outFile.setf(ios::fixed);
  outFile.setf(ios::showpoint);
  outFile.precision(2);
  outFile << rd.id<< setw(10) << rd.exam1 << setw(10) << rd.exam2 << setw(10) << rd.exam3 << setw(10) << rd.avg << setw(10) << rd.passFail << endl;
}
void StudRd :: WriteInvalidRd(ofstream& outFile, StudRd rd)
{
  outFile.setf(ios::fixed);
  outFile.setf(ios::showpoint);
  outFile.precision(2);
  outFile << rd.id << setw(10) << rd.exam1 << setw(10) << rd.exam2 << setw(10) << rd.exam3 << setw(10) << "Invalid Data" << endl;
}
void StudRd :: WriteFooterRd(ofstream& outFile, StudRd rd)
{
  outFile.setf(ios::fixed);
  outFile.setf(ios::showpoint);
  outFile.precision(2);
  outFile << ">>> Max of All Valid Exams: " << rd.examMax << endl;
  outFile << ">>> Average of All Valid Exams: " << rd.avgOfAllExams << endl;
  outFile << endl;
  outFile << "Number of Valid Data: " << rd.numValid << "   Number of Invalid Data: " << rd.numInvalid << endl;
  outFile << "Number of Students Passed: " << rd.numPass << "   Number of Students Failed: " << rd.numFail << endl;
}
void StudRd :: findAvg(StudRd& rd)
{
  rd.avg = float(rd.exam1 + rd.exam2 + rd.exam3)/float(3);
  rd.examSum = rd.examSum + rd.avg;
  if(rd.avg < 70){
    rd.passFail = "F";
    numFail++;
  }
  else{
    rd.passFail = "P";
    numPass++;
  }
}


#include <fstream>
#include <iostream>
#include <iomanip>
using namespace std;
//Creates the structure Studrd
class StudRd
{
  public:
  void DefaultRd();
  bool ValidRd(StudRd& rd) const;
  void ValidCountRd(StudRd& rd);
  void InvalidCountRd(StudRd& rd);
  void MaxOfAllExams(StudRd& rd);
  void AvgOfAllExams(StudRd& rd);
 void ReadRd(ifstream& inFile, StudRd& rd);
 void WriteRd(ofstream& outFile, StudRd rd);
 void WriteInvalidRd(ofstream& outFile, StudRd rd);
 void WriteFooterRd(ofstream& outFile, StudRd rd);
  void findAvg(StudRd& rd);
 private:
  int id;
  int numValid;
  int numInvalid;
  int numPass;
  int numFail;
  float exam1;
  float exam2;
  float exam3;
  float avg;
  float examMax;
  float avgOfAllExams;
  float examSum;
  string passFail;
};

我不知道是什么原因造成的，也不知道对此有任何帮助，所以我至少可以让它编译，这样我就可以进行最后的调整，我将不胜感激。

如果有人发现错误，他们可以指出并解释出了什么问题，那将是非常好的。

也是我第一次提交希望我做对了。