C++ 错误 : no match for call to '(Vector3 (double, double, double)'

Question

所以我有这个错误阻止我继续我的任务。
这是代码:

#include "std_lib_facilities.h"

class Vector3
{
public:
    Vector3();
    Vector3(double x1);
    Vector3(double x1, double y1);
    Vector3(double x1, double y1, double z1);

//Helper functions
    double x() {return x1;}
    double y() {return y1;}
    double z() {return z1;}


private:
    double x1,y1,z1;
};

/** Constructor Definitions **/
Vector3::Vector3(double x, double y, double z){
    x1=x;
    y1=y;
    z1=z;
}
Vector3::Vector3(double x, double y){
    x1=x;
    y1=y;
}
Vector3::Vector3(double x){
    x1=x;
}
Vector3::Vector3()
{
    x1=0;
    y1=0;
    z1=0;
}

/** Operator Overloading **/

ostream& operator<<(ostream&os, Vector3& v) //<< Overloading
 {
    return os <<"["<<v.x()
              <<", "<<v.y()
              <<", "<<v.z()
              <<"]"<<endl;
}

Vector3 operator+(Vector3 v1, Vector3 v2) //+ Overloading
{
    double a,b,c;
    Vector3 vector1(a,b,c);
    return vector1( v1.x()+v2.x() , v1.y()+v2.y() , v1.z()+v2.z() );
}

这是一个头文件。错误发生在返回行的//+Overloading(代码的最后一位)。
我用谷歌搜索但无济于事。大多数人建议我使用与其他名称相同的函数或变量，但我找不到类似的东西。

Answer 1

Vector3 vector1(a,b,c);    
return vector1( v1.x()+v2.x() , v1.y()+v2.y() , v1.z()+v2.z() );

首先，您要使用未初始化的变量构造一个 Vector3 对象。然后您尝试对该对象调用调用运算符 (operator())。您的 operator+ 函数可能看起来像这样:

Vector3 operator+(Vector3 v1, Vector3 v2) //+ Overloading
{
    return Vector3( v1.x()+v2.x() , v1.y()+v2.y() , v1.z()+v2.z() );
}