重载运算符参数加const
/*求复数相加*/#include<iostream>
using namespace std;
class Complex
{
public:
Complex()
{
real=0;
imag=0;
}
Complex(double t,double d)
{
real=t;
imag=d;
}
Complex operator +(const int &x); /*不加const显示编译错误*/
void display()
{
cout<<"("<<real<<","<<imag<<"!)"<<endl;
}
private:
double real;
double imag;
};
Complex Complex::operator +(const int &x) /*不加const显示编译错误*/
{
return Complex(real+x,imag);
}
int main()
{
Complex t1(3.4,5.2);
Complex t3,t4;
t3=t1+2;
t3.display();
return 0;
}
不加const编译通不过，这是为什么呢，我也不需要改变int的值呀 不应该的，看你编译器，你的编译器错误信息是什么
#include<iostream>
using namespace std;
class Complex
{
public:
Complex()
{
real=0;
imag=0;
}
Complex(double t,double d)
{
real=t;
imag=d;
}
Complex operator +(int &x); /*不加const显示编译错误*/
void display()
{
cout<<"("<<real<<","<<imag<<"!)"<<endl;
}
private:
double real;
double imag;
};
Complex Complex::operator +(int &x) /*不加const显示编译错误*/
{
return Complex(real+x,imag);
}
int main()
{
Complex t1(3.4,5.2);
Complex t3,t4;
//t3=t1+2; // 是这里导致的，加const就是为了这里
int a = 1234;
t3 = t1 + a;
t3.display();
return 0;
}
time1970 发表于 2020-3-29 14:36
不应该的，看你编译器，你的编译器错误信息是什么
c.cpp(35) : error C2679: binary '+' : no operator defined which takes a right-hand operand of type 'const int' (or there is no acceptable conversion)
执行 cl.exe 时出错.
声明和下面定义都不加const会显示如上错误
#include <iostream>
int main()
{
int a = 1234;
int &r1 = a;
//int &r2 = 1234; // 这个就不行
const int &r3 = 1234; // 没问题
return 0;
}
大河之jian 发表于 2020-3-29 14:42
c.cpp(35) : error C2679: binary '+' : no operator defined which takes a right-hand operand of type ...
楼下正解，引用只能对左值，常引用才可以引用右值
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