else
{
    //error situation
}

Re eating one's own dogfood: We have the same term in our workplace (granted, only because I introduced it). My code is peppered with comments that say "TODO" and indicate something that ought to be done eventually, but a comment saying "DOGFOOD" (both keywords are always at the beginning of the comment, in all caps) means something that must be done before this program can be used even internally. It's a handy thing to search for, as the word "dogfood" is never going to appear in a quoted string - if it does, I can always just say "dog-food" or something - so even a case-insensitive search will come up with the right results.

Regarding zeroing the accumulator: I've done exactly the same thing when programming an Intel 80x86 (I started on the 8086 and moved up from there into the modern Pentiums). XORing a register with itself is the quickest and tightest way to clear it. Using "MOV AX,0" requires three bytes (opcode and two bytes of literal 16-bit zero), whereas "XOR AX,AX" is only two; it's even more noticeable with the 386-and-higher extended registers, where "MOV EAX,0" requires five bytes (four bytes of 32-bit zero). My C/C++ compiler always zeroes registers this way, so I'd assume it's still the best way (although I haven't studied opcode timing tables in ages, and probably both XOR reg,reg and MOV reg,imm take one clock).

aComment = 'this is not aComment' # this is aComment
class T(object):
    def f(this):
        this is not aComment

// This procedure is really good for your dorsolateral prefrontal cortex.

你们中有些人，由于某种特殊的原因，不知道DPC，当你深入学习新东西时，你大脑的这一部分会亮起来。

在一个著名的商业DOS电子表格应用程序中:

/* This comment was just added in order to check-in a file that was last 
checked in by [Insert Programmer FirstName] "Back-to-the-Future" [Insert 
Programmer LastName]. While testing for year 2000 problems, he accidentally 
checked-in this file while his machine clock was set forward to the year 2000. 
This meant that the source code was always newer than the object file and 
compiled every time the code was built. I'm checking this file in again to 
fix that. */

// barcore.cpp - MFC

//.....
HBRUSH CControlBar::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
    LRESULT lResult;
    if (pWnd->SendChildNotifyLastMsg(&lResult))
        return (HBRUSH)lResult;     // eat it

//......

// Eat it - just like eat this.