C++之inline

//head.h
#ifndef HEAD_H
#define HEAD_H
inline int f(int i);
#endif

//head.cpp
#include "head.h"
inline int f(int i)
{
	return i * i;
}

//inline test
//main.cpp
#include <iostream>
#include "head.h"
int main()
{
	std::cout << f(2);
	return 0;
}

//result: this is wrong!