实用的程序员编程工具

				#include 
				
				float sample_function(float i);
				double sample_function(double i);
				
				void main(void)
				{
					cout 				   cout 				}
				
				float sample_function(float i)
				{
					return i;
				}
				
				double sample_function(double i)
				{
					return -i;
				}