利用union判断CPU是大端模式还是小端模式

#include <iostream>
using namespace std;

int checkCPU()
{
	union w
	{
		int a;
		char b;
	} c;
	c.a = 1;
	return c.b == 1;//如果低地址还是1说明低地址存放低字节，小端 
}//如果低地址不是1，则高地址是1，说明低地址存放高字节，大端 

int main()
{
	if (checkCPU())
	{
		cout << "The endian of cpu is little \n";
	}
	else
	{
		cout << "The endian of cpu is big \n";
	}
	return 0;
}