c++函数功能 引用 & 重载 & 默认参数 & 内联

/*
c++新功能小程序
引用 & 重载 & 默认参数 & 内联
*/
#include<iostream>
inline double square(double x = 2);
inline double square2(double &x);
int fun(int a, int b);
double fun(double a, double b);
int main()
{
double a;
std::cin >> a;
std::cout << square(a) << std::endl;
std::cout << square() << std::endl;
double & b = a;
b = square2(b);
std::cout << b << std::endl;
std::cout << a << std::endl;
int aa = 2, bb = 2;
std::cout << fun(aa, bb) << std::endl;
double aaa = 2.2, bbb = 2.2;
std::cout << fun(aaa, bbb) << std::endl;
return 0;
}
inline double square(double x)
{
return x * x;
}
inline double square2(double &x)
{
return x * x;
}
int fun(int a, int b)
{
return a + b;
}
double fun(double a, double b)
{
return a * b;
}