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如果我将它作为指向内存的指针作为指向短裤的指针：

unsigned short* ms = reinterpret_cast<unsigned short*>(_memory);

而且我知道 ms 的大小（这条短裤的数量），我希望看到所有这些短裤及其二进制表示形式的运行。

如何访问 C++ 中每个短路的位？

4

5 回答 5

4

要查看任何类型变量的二进制表示T，您可以执行以下操作：

template <typename T>
void print_raw(const T & x)
{
  const unsigned char * const p = reinterpret_cast<const unsigned char *>(&x);
  for (std::size_t i = 0; i != sizeof(T); ++i)
  {
    if (i != 0) std::putchar(' ');
    std::printf("%02X", p[i]);
  }
}

您可以将其插入短裤列表。

（您甚至可以printf用两个索引查找p[i] / 16和p[i] % 16合适的字母表替换：

static const char alphabet = "01234567890ABCDEF";
std::putchar(alphabet[p[i] / 16]);
std::putchar(alphabet[p[i] % 16]);

或者用真正的二进制打印机替换它：

void print_byte(unsigned char b)
{
  for (std::size_t i = CHAR_BIT; i != 0; --i)
  {
    std::putchar(b & (1u << (i-1)) ? '1' : '0');
  }
}

您可以将其链接到前一个循环而不是两个printf调用。）

于 2011-11-15T20:51:05.637 回答
3 
cout << "\t" << dec << x << "\t\t Decimal" << endl;
cout << "\t" << oct << x << "\t\t Octal" << endl;
cout << "\t" << hex << x << "\t\t Hex" << endl;
cout << "\t" << bitset<MAX_BITS>(x) << endl;

尝试通过位集

编辑（添加代码）

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

int main( int argc, char* argv[] )
{
  unsigned short _memory[] = {0x1000,0x0010,0x0001};
  unsigned short* ms = reinterpret_cast<unsigned short*>(_memory);
  for(unsigned short* iter = ms; iter != ms + 3/*number_of_shorts*/; ++iter )
  {
    bitset<16> bits(*iter);
    cout << bits << endl;
    for(size_t i = 0; i<16; i++)
    {
      cout << "Bit[" << i << "]=" << bits[i] << endl;
    }
    cout << endl;
  }
}

或者

#include <iostream>
#include <algorithm>
#include <bitset>
#include <iterator>

int main( int argc, char* argv[] )
{
    unsigned short _memory[] = {0x1000,0x0010,0x0001};
    unsigned short* ms = reinterpret_cast<unsigned short*>(_memory);
    unsigned int num_of_ushorts = 3;//

    std::copy(ms, ms+num_of_ushorts, ostream_iterator<bitset<16>>(cout, " "));
}
于 2011-11-15T20:54:27.460 回答
0

作为_memory指向短裤列表的指针，您的ms指针可以用作数组。

unsigned short* ms = reinterpret_cast<unsigned short*>(_memory);

for (int i = 0; i < NUM_SHORTS_IN_MEM; i++)
    cout << i << "th element\t" << ms[i] << endl;
于 2011-11-15T20:50:57.920 回答
0

If you are working under the assumption that an unsigned short has 16 bits, then you can retrieve each of them with bitwise operations:

for( unsigned short* iter = ms; iter != ms + num_of_ushorts; ++iter )
{
    int bitN = ( *iter ) & ( 1 << N ); // get the N bit
}
于 2011-11-15T20:47:16.610 回答
0 
for (size_t i=0; i<N_SHORTS_IN_BUFFER; i++)
    // perform bitwise ops

哪里N_SHORTS_IN_BUFFER是短裤的数量memory。

a 中的位数short是CHAR_BIT * sizeof(short)。

于 2011-11-15T20:44:54.153 回答