c++ - 没有候选错误编译错误

Question

我正在尝试编译我的应用程序，但它一直遇到“不匹配'operator<<'...目前尚不清楚程序的确切错误似乎是什么，因为他的对象配置正确我能看到。

#include <iostream>
#include <conio.h>
#include <cmath>
#include <stdexcept>

using namespace std;
class MortgageCalc
{
protected:
    float term;
public:
    void setData(float, float, float);
    float setTerm ();
    float monthly;
    float total;
    float interest;
        float setLoan(void);  //mutator
        float setIntrest(void);     //mutator
        float setYears(void);
    int years;
    float loan;
};

void MortgageCalc::setData(float l, float i, float y)
{
   loan = l;
   interest = i;
   years = y;
   setTerm();
}

float MortgageCalc::setTerm()
{  //simple interest calculation with power calc to establish whole number translation
     term = pow((1 + ((interest/100) / 12)), (12 * years));
     return term;
}

float MortgageCalc::setLoan(void)
{  //returns loan amt to private member
   return loan;
}

float MortgageCalc::setIntrest(void)
{  //returns interest amt to private member
    return interest;
}

float MortgageCalc::setYears(void)
{  //returns years to private member
   return years;
}

class mPayment : public MortgageCalc
{
public:
    int monthly()
    {
        return ((loan * ((interest/100) / 12) * term ) / (term - 1));
    }
};

class tPayment : public mPayment
{
public:
    int total()
    {
        return (monthly() * (years * 12));

    }
};

class iPayment : public tPayment
{
public:
    int plusInterest()
    {
        return (total() - loan);
    }
};

int main()
{
double loan(0), interest(0);
int years = 0;
MortgageCalc mort1;

    cout << "Enter the total loan amount on your mortgage loan: $";  //established loan variable
        cin >> loan;
    cout << "Enter the interest rate (in whole #'s only): ";  //establishes interest rate variable
        cin >> interest;
    cout << "Enter the length of the loan in years: "; //establishes term of payments
        cin >> years;
mort1.setData(loan, interest, years);

mPayment m;
       cout << "Monthly payment due is " << m.monthly() << "." << endl;

tPayment t;
        cout << "Total payment will be " << t.total() << "." << endl;

iPayment i;
        cout << "Total payment plus Interest will be " << i.plusInterest() << "." << endl;

return 0;
};

Answer 1

cout << "Total payment plus Interest will be " << i.plusInterest << "." << endl;

plusInterest 是类方法指针。不出所料，std::ostream 不知道如何处理类方法指针，并且正确地表达了强烈的反对意见，反对这样一个荒谬的提议，它知道如何处理一些奇怪的类的方法指针。

你可能打算写:

cout << "Total payment plus Interest will be " << i.plusInterest() << "." << endl;

现在，这是一个正确的函数调用，它返回一个 int，std::ostream 现在很高兴接受这个 int，并用它施展魔法。