c++ - 复数模板类

Question

#ifndef COMPLEXNUMBER_H
#define COMPLEXNUMBER_H

#include <iostream>

using namespace std;

template <class T>
class ComplexNumber
{

    friend ostream& operator<<(ostream&, const ComplexNumber&);
    friend istream& operator>>(istream&, ComplexNumber&);
public:

    void setComplexNumber(const T&, const T&);
    T getComplexNumber(T&, T&) const;
    ComplexNumber();
    ComplexNumber(T real , T imaginary);
    T operator+(const ComplexNumber&)const;
    T operator-(const ComplexNumber&)const;
    T operator*(const ComplexNumber&)const;
    T operator/(const ComplexNumber&)const;
    T& operator=(const ComplexNumber&);
    bool operator==(const ComplexNumber&) const;
    bool operator!=(const ComplexNumber&) const;

private:

    T realnumber;
    T imaginarynumber;
};

template<class T>
ostream& operator<<(ostream& out, const ComplexNumber<T>& complex)
{

    out<<complex.realnumber;
    out<<"+";
    out<<complex.imaginarynumber;
    out<<"i";
    return out;
}

template <class T>
istream& operator>>(istream& in, ComplexNumber<T>& complex)
{
    char ch;
    in>>complex.realnumber;
    in>>complex.imaginarynumber;
    in>>ch;
    return in;
}

template <class T>
T& ComplexNumber<T>::operator=(const ComplexNumber& other)
{
    if (this != &other)
    {
        realnumber = other.realnumber;
        imaginarynumber = other.imaginarynumber;
    }

    return  *this;
}

template <class T>
bool ComplexNumber<T>::operator ==(const ComplexNumber& other) const
{
    return (realnumber == other.realnumber && imaginarynumber == other.imaginarynumber);
}

template<class T>
bool ComplexNumber<T>::operator !=(const ComplexNumber& other) const
{
    return (realnumber != other.realnumber && imaginarynumber != other.imaginarynumber);
}


//Default Constructor
template<class T>
ComplexNumber<T>::ComplexNumber()
{
    realnumber = 0.0;
    imaginarynumber = 0.0;
}


//Constructor which takes in two arguments
template<class T>
ComplexNumber<T>::ComplexNumber(const T real,const T imaginary)
{
    realnumber = real;
    imaginarynumber = imaginary;
}

template<class T>
void ComplexNumber<T>::setComplexNumber(const T& real, const T& imaginary)
{
    realnumber = real;
    imaginarynumber = imaginary;
}

//Overloaded Addition Operator
template<class T>
T ComplexNumber<T>::operator +(const ComplexNumber& other) const
{
    ComplexNumber<T>temp;
    temp.realnumber = realnumber + other.realnumber;
    temp.imaginarynumber = imaginarynumber + other.imaginarynumber;
    return ComplexNumber;
}

//Overloaded subtraction operator
template<class T>
T ComplexNumber<T>::operator -(const ComplexNumber& other) const
{
    ComplexNumber<T> temp;
    temp.realnumber = realnumber - other.realnumber;
    temp.imaginarynumber = imaginarynumber - other.imaginarynumber;
    return temp;
}

//Overloaded multiplication operator
template<class T>
T ComplexNumber<T> ::operator *(const ComplexNumber& other)const
{
    ComplexNumber<T> temp;
    temp.realnumber = (realnumber * other.realnumber) - (imaginarynumber * other.imaginarynumber);
    temp.imaginarynumber = (realnumber * other.imaginarynumber) + (imaginarynumber * other.realnumber); 
    return temp;
}

//Overloaded division operator
template<class T>
T ComplexNumber<T> ::operator/(const ComplexNumber& other)const
{
    ComplexNumber<T> temp;  
    temp.realnumber = ((realnumber * other.realnumber) + (imaginarynumber * other.imaginarynumber))/((pow(other.realnumber,2.0))+(pow(other.imaginarynumber,2.0)));
    temp.imaginarynumber = ((other.realnumber * imaginarynumber) - (realnumber * other.imaginarynumber))/((pow(other.realnumber,2.0))+(pow(other.imaginarynumber,2.0))); 
    return temp;
}


#endif

我遇到一个问题，我的加法、减法、乘法和除法运算符无法从 ComplexNumber 转换为 double 或我想要的任何其他数据类型。请让我知道我做错了什么。谢谢。

Answer 1

//Overloaded Addition Operator
template<class T>
T ComplexNumber<T>::operator +(const ComplexNumber& other) const
{
    ComplexNumber<T>temp;
    temp.realnumber = realnumber + other.realnumber;
    temp.imaginarynumber = imaginarynumber + other.imaginarynumber;
    return ComplexNumber;
}

我需要

return temp;

在这里编译。这就是你要问的吗？

此外，在这种情况下，您可能希望该方法返回 ComplexNumber<T> , 不是 T .这可能就是您遇到的转换问题。它正在尝试转换 ComplexNumber<T>至 T回来。和 T我猜在您运行的任何示例中都是双倍的。

其他一些问题。 friend 声明需要是一个模板。还有一些其他的东西。但这是一个功能版本。至少它对我有用。它需要重新添加其他运算符。

#include <iostream>

using namespace std;

template <class T>
class ComplexNumber
{
public:
    ComplexNumber();
    ComplexNumber(T real , T imaginary);
    ComplexNumber<T> operator+(const ComplexNumber<T>&)const;

    template <class U> 
    friend ostream& operator<<(ostream&, const ComplexNumber<U>&);

private:
    T realnumber;
    T imaginarynumber;
};

//Default Constructor
template<class T>
ComplexNumber<T>::ComplexNumber()
{
    realnumber = 0.0;
    imaginarynumber = 0.0;
}


//Constructor which takes in two arguments
template<class T>
ComplexNumber<T>::ComplexNumber(const T real,const T imaginary)
{
    realnumber = real;
    imaginarynumber = imaginary;
}

//Overloaded Addition Operator
template<class T>
ComplexNumber<T> ComplexNumber<T>::operator +(const ComplexNumber<T>& other) const
{
    ComplexNumber<T> temp;
    temp.realnumber = realnumber + other.realnumber;
    temp.imaginarynumber = imaginarynumber + other.imaginarynumber;
    return temp;
}

template<class T>
ostream& operator<<(ostream& out, const ComplexNumber<T>& complex)
{
    out<<complex.realnumber;
    out<<"+";
    out<<complex.imaginarynumber;
    out<<"i";
    return out;
}

int main(){
  ComplexNumber<double> cn1(1,1);
  ComplexNumber<double> cn2(1,1);
  ComplexNumber<double> cn3 = cn1+cn2;
  cout<<cn3<<endl;
}