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目标：正确快速地将数组从 char 转换为 unsigned int。

检查我的工作 - 请：

...
// NOTE:
// m_chFileBuffer is a member/variable from a class.
// m_nFileSize is also a member/variable from a class.
// iFile is declared locally as std::ifstream

// Calculate the size of iFile and copy the calculated
// value to this->m_nFileSize
iFile.seekg( 0, std::ios::end );
this->m_nFileSize = iFile.tellg( );
iFile.seekg( 0, std::ios::beg );

// Declare this->m_chFileBuffer as a new char array
this->m_chFileBuffer = new char[ this->m_nFileSize ];

// Read iFile into this->m_chFileBuffer
iFile.read( this->m_chFileBuffer, this->m_nFileSize );

// Declare a new local variable
::UINT *nFileBuffer = new ::UINT[ this->m_nFileSize ];

// Convert this->m_chFileBuffer from char to unsigned int (::UINT)
// I might be doing this horribly wrong, but at least I tried and
// will end up learning from my mistakes!
for( ::UINT nIndex = 0; nIndex != this->m_nFileSize; nIndex ++ )
{
    nFileBuffer[ nIndex ] = static_cast< ::UINT >( this->m_chFileBuffer[ nIndex ] );

    // If defined DEBUG, print the value located at nIndex within nFileBuffer
    #ifdef DEBUG
    std::cout << nFileBuffer[ nIndex ] << ' ';
    #endif // DEBUG
}

// Do whatever with nFileBuffer
...

// Clean-up
delete [ ] nFileBuffer;

有事吗？： 如果有更好的方法来完成目标，请在下方留言！

更多： 是否可以将此概念应用于 unsigned int std::vector？

4

2 回答 2

4

对于这样一个简单的任务来说，代码太多了，你只需要这个。

std::vector <unsigned int> v;
std::copy (std::istream_iterator <char> (iFile), 
           std::istream_iterator <char> (), 
           std::back_inserter (v));

甚至更短（感谢@111111）：

std::vector <unsigned int> v 
{ 
       std::istream_iterator <char> (iFile),
       std::istream_iterator <char> ()
};
于 2013-02-25T11:07:44.160 回答
0 
vector<char> buf(file_size);
/* read file to &buf[0] */
vector<unsigned int> uints(buf.size());
copy(buf.begin(), buf.end(), uints.begin());

您的原始 new/delete-usage 不是异常安全的。经验法则：永远不要在你的代码中写 delete，只要你不是自己写析构函数。此外，可能会签署“char”，但不确定您在那里期待什么行为。

于 2013-02-25T11:10:30.880 回答