重载运算符作为成员函数

Question

I'm working on a vector class and am trying to overload some operators. I've looked at countless examples, tried every alteration I can think of, and still g++ is complaining

include/vector.cpp:9:38: error: no ‘vec vec::operator+(const vec&)’ member function declared in class ‘vec’

Obviously g++ is telling me that I'm defining a member function but that I haven't declared my operator as a member function.

Here is the code (I've omitted most of it as it is working fine and is not relevant): vec.h

#ifndef _BEN_VECTOR
#define _BEN_VECTOR

#include <math.h>
#include <string>
#include <sstream>
class vec{
public:
    /* Constructor */
    vec(double X, double Y);
    /* OPERATORS */
    vec operator+( const vec& other);

private:
    int dims;
    double x;
    double y;
};
#endif /* _BEN_VECTOR */

vec.cpp:

#include "vector.h"

/* CONSTRUCTORS */
vec::vec(double X, double Y){
    x = X; y = Y; dims = 2;
}

/* OPERATORS */
vec vec::operator+( const vec& other ){
    vec v(this->gety() + other->getx(), this->gety() + other->gety());
    return v;
}

Sorry if this is a duplicate -- I've been scouring the interwebz for hours now and haven't found anything. I'm sure I'll be embarrassed when I see how obvious my mistake is :) Thanks

Answer 1

Here is part of my Vector2 class maybe this will help you.

class Vector2 {
public:
    union {
        float m_f2[2];
        struct {
            float m_fX;
            float m_fY;
        };
    };

    inline Vector2();
    inline Vector2( float x, float y );
    inline Vector2( float* pfv );

    // ~Vector2(); // Default Okay

    // Operators
    inline Vector2 operator+() const;
    inline Vector2 operator+( const Vector2 &v2 ) const;
    inline Vector2& operator+=( const Vector2 &v2 );

};

inline Vector2::Vector2() : 
m_fX( 0.0f ),
m_fY( 0.0f ) {
}

inline Vector2::Vector2( float x, float y ) :
m_fX( x ),
m_fY( y ) {
}

inline Vector2::Vector2( float* pfv ) :
m_fX( pfv[0] ),
m_fY( pfv[1] ) {
}

// operator+() - Unary
inline Vector2 Vector2::operator+() const {
    return *this; 
}

// operator+() - Binary
inline Vector2 Vector2::operator+( const Vector2 &v2 ) {
    return Vector2( m_fX + v2.m_fX, m_fY + v2.m_fY );
}

// Operator+=()
inline Vector2& Vector2::operator+=( const Vector2 &v2 ) {
    m_fX += v2.m_fX;
    m_fY += v2.m_fY;
    return *this;
}