猫史档案馆

#include<iostream>
#include<cmath> 
using namespace std;
struct position{
	int x; 
	int y; 
	int z; 
}; 
class entity{
	public:
 		static position forward(position originally,double derection,int distance){
		    if(derection>0&&derection<=45){
		    	originally.x+=round(sin(direction))*distance;
		    	originally.z+=round(cos(direction))*distance;
		    }else if(derection>45&&derection<=90){
		        originally.x+=round(cos(direction))*distance;
		        originally.z+=round(sin(direction))*distance;
	        }else{
	    	    return derection<0?entity::forward(originally,derection+90,distance):entity::forward(originally,derection-90,distance);
	        }
	        return originally;
        }
	private:
		static position pos;
		static int direction;
};

int main(){
	position xyz={255,127,255};
	cout<<entity::forward(xyz,0.0,100);
	return 0;
}

报错：[Error] no match for 'operator<<' (operand types are 'std::ostream {aka std::basic_ostream<char>}' and 'position')

就是这样的，到底是哪里错了？