好吧,我正在为我的类编写这段代码,我正在使用Visual Studio获得链接器错误LNK2019和LNK1120。我不太清楚它为什么要这么做,但我离题了。
头文件:
#ifndef PointClass
#define PointClass
#include <iostream>
namespace PointClass
{
class point
{
public:
// CONSTRUCTOR
point(double initial_x = 0.0, double initial_y = 0.0);
// MODIFICATION MEMBER FUNCTIONS
void shift(double x_amount, double y_amount);
void rotate90( );
// CONSTANT MEMBER FUNCTIONS
double get_x( ) const { return x; }
double get_y( ) const { return y; }
// FRIEND FUNCTION
friend std::istream& operator >>(std::istream& ins, point& target);
double x, y; // x and y coordinates of this point
};
// NONMEMBER FUNCTIONS for the point class
double distance(const point& p1, const point& p2);
point middle(const point& p1, const point& p2);
point operator +(const point& p1, const point& p2);
bool operator ==(const point& p1, const point& p2);
bool operator !=(const point& p1, const point& p2);
std::ostream& operator <<(std::ostream & outs, const point& source);
}
#endif
以及CPP文件:
#include <iostream>
#include <math.h>
#include "point.h"
using namespace std;
namespace PointClass
{
point::point(double initial_x, double initial_y)
{
x = initial_x; // Constructor sets point to a given position
y = initial_y;
}
void point::shift(double x_amount, double y_amount)
{
x += x_amount;
y += y_amount;
}
void point::rotate90( )
{
double new_x;
double new_y;
new_x = y; // For a 90 degree clockwise rotation the new y is -1
new_y = -x; // times original x, and the new x is the original y
x = new_x;
y = new_y;
}
bool operator ==(const point& p1, const point& p2)
{
return
(p1.get_x( ) == p2.get_x( ))
&&
(p1.get_y( ) == p2.get_y( ));
}
bool operator !=(const point& p1, const point& p2)
{
return !(p1 == p2);
}
point operator +(const point& p1, const point& p2)
{
double x_sum, y_sum;
// Compute the x and y of the sum:
x_sum = (p1.get_x( ) + p2.get_x( ));
y_sum = (p1.get_y( ) + p2.get_y( ));
point sum(x_sum, y_sum);
return sum;
}
ostream& operator <<(ostream& outs, const point& source)
{
outs << source.get_x( ) << " " << source.get_y( );
return outs;
}
istream& operator >>(istream& ins, point& target)
{
ins >> target.x >> target.y;
return ins;
}
int rotations_needed(point p)
{
int answer;
answer = 0;
while ((p.get_x( ) < 0) || (p.get_y( ) < 0))
{
p.rotate90( );
++answer;
}
return answer;
}
void rotate_to_upper_right(point& p)
{
while ((p.get_x( ) < 0) || (p.get_y( ) < 0))
p.rotate90( );
}
double distance(const point& p1, const point& p2)
{
double a, b, c_squared;
// Calculate differences in x and y coordinates
a = p1.get_x( ) - p2.get_x( ); // Difference in x coordinates
b = p1.get_y( ) - p2.get_y( ); // Difference in y coordinates
// Pythagorean Theorem to calculate square of distance between points
c_squared = a*a + b*b;
return sqrt(c_squared); // sqrt calculates square root
}
point middle(const point& p1, const point& p2)
{
double x_midpoint, y_midpoint;
// Compute the x and y midpoints
x_midpoint = (p1.get_x( ) + p2.get_x( )) / 2;
y_midpoint = (p1.get_y( ) + p2.get_y( )) / 2;
// Construct a new point and return it
point midpoint(x_midpoint, y_midpoint);
return midpoint;
}
}
我能做些什么来修理它吗?
最佳答案
您似乎有一个名为PointClass的命名空间,而headers则使用PointClass进行保护。先考虑改变一下。
#ifndef PointClass // Rename this, it might be clashing with your namespace.
#define PointClass
namespace PointClass