c++ - 将 MSB 优先转换为 LSB 优先

Question

我想将无符号短值从 MSB 优先转换为 LSB 优先。做了下面的代码，但它不工作。有人可以指出我所做的错误吗

#include <iostream>
using namespace std;
int main()
{
  unsigned short value = 0x000A;
  char *m_pCurrent = (char *)&value;
  short temp;
  temp = *(m_pCurrent+1);       
  temp = (temp << 8) | *(unsigned char *)m_pCurrent;
  m_pCurrent += sizeof(short); 
  cout << "temp    " << temp << endl; 
  return 0;
}

Answer 1

这是一个简单但缓慢的实现:

#include <cstdint>

const size_t USHORT_BIT = CHAR_BIT * sizeof(unsigned short);

unsigned short ConvertMsbFirstToLsbFirst(const unsigned short input) {
  unsigned short output = 0;
  for (size_t offset = 0; offset < USHORT_BIT; ++offset) {
    output |= ((input >> offset) & 1) << (USHORT_BIT - 1 - offset);
  }
  return output;
}

您可以轻松地将其模板化以处理任何数字类型。