从《雷神之锤III》的资料中，我在一些随机的帖子中偶然发现了这一点。该文件的完整源代码可以在这里找到。这是一种非常快速的求平方根倒数的方法。至于最好的评论呢?当然，这是一种常见的方法，但考虑到它附着在直线上，它的神奇之处在于它的伟大之处。

float Q_rsqrt( float number )
{
  long i;
  float x2, y;
  const float threehalfs = 1.5F;

  x2 = number * 0.5F;
  y  = number;
  i  = * ( long * ) &y;  // evil floating point bit level hacking
  i  = 0x5f3759df - ( i >> 1 ); // what the fuck?
  y  = * ( float * ) &i;
  y  = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration
  // y  = y * ( threehalfs - ( x2 * y * y ) ); // 2nd iteration, this can be removed

  #ifndef Q3_VM
  #ifdef __linux__
    assert( !isnan(y) ); // bk010122 - FPE?
  #endif
  #endif
  return y;
}

多年前，我遇到了这样一个问题:

/***************************************************************************/
/*  deep wizardry. do not touch.                                           */
/*                                                                         */
/*  no seriously.  XXXXXX I'm looking at you. If you screw with this again */
/*  I will kill you with my swingline stapler.                             */
/*                                                                         */
/* ...                                                                     */

然后描述了一个特别复杂的算法。

这是我们在大学宿舍使用的自定义DHCP服务器，根据它们是否注册/安装补丁和防病毒，将计算机放入“干净”或“脏”IP地址池:

public boolean getDirty (String MAC) // not as fun as it sounds

// BEGIN HACK
...
// END HACK: I feel dirty.

struct core_unlocker
{
    core_unlocker(lock)
    {
        m_lock = lock
        unlock(lock)  //Abandon All Locks, Ye Who Enter Core!
    }
    ~core_unlocker()
    {
        lock(m_lock)
    }  
    private:
    Corelock m_lock;
}

我刚刚在。net的自定义Linq提供程序中找到了这个:

//select is a royal pain in the ass where 
//the parameter passed to CreateQuery isn't actually the one that goes in the call
//requiring this workaround.  Not sure how straight Linq to Objects does it.

还有这个

//expressions have to be compiled in order to work with the method call on 
//straight Enumerable somehow, LINQ to objects itself magically does this.  
//Reflector shows a mess, so I (Aaron) invented my own way.  God love unit tests!

我刚刚也找到了这个…一切都会变得更好

  //ok, this is a hairy, dirty, and nasty piece of code
  //the alternatives are substantially worse than this though
  //i.e. when you do your own provider, LINQ assumes that
  //you are going to implement your own expression tree visitor and
  //do it all yourself.  Frankly, I still have xmas shopping to do
  //and I really don't want us to be foobared when we get
  //even more extension methods added to LINQ
  //therefore, we are pulling execute based on taking the calling the 
  //standard execute on enumerable, but using our own class
  //
  //optimization can occur from here on an as needed basis, that is
  //check for the value of mex.Method.Name, and write a handler for
  //that method
  //
  //also, it may not be a bad idea to rather than do this reflection 
  //each and every time somehow cache the reflected methodinfos and do 
  //lookups that way that said, we need a complete red/green/refactor 
  //cycle here before I am touching that one

还有这个

//Compile that mutherf-ker, invoke it, and get the resulting hash