C++二進制輸出及循環移位運算

大多數計算機處理器提供了機器級的循環命令，但在C和C++中，不直接支持循環，因此需要創建自己的循環命令。下面是實現左旋和右旋的函數：

#include <iostream>
#include <bitset>
using namespace std;

void rol(unsigned char& val) {
    int highbit;
    if (val & 0x80)
        highbit = 1;
    else
        highbit = 0;
    val <<= 1;
    val |= highbit;
}

void ror(unsigned char& val) {
    int lowbit;
    if (val & 0x01)
        lowbit = 1;
    else
        lowbit = 0;
    val >>= 1;
    val |= lowbit;
}

int main()
{
	unsigned char x = 127;
    cout << bitset<sizeof(unsigned char) * 8>(x) << endl;
    rol(x);
    cout << bitset<sizeof(unsigned char) * 8>(x) << endl;
    ror(x);
    cout << bitset<sizeof(unsigned char) * 8>(x) << endl;

    system("pause");
	return 0;
}