The Old New Thing

How did the X-Mouse setting come to be?

Commenter HiTechHiTouch wants to know whether the "X-Mouse" feature went through the "every request starts at −100 points filter", and if so, how did it manage to gain 99 points? The X-Mouse feature is ancient and long predates the "−100 points" rule. It was added back in the days when a developer could add a random rogue ...

Adventures in undefined behavior: The premature downcast

A customer encountered the following problem: The function converts the cookie back to a object, and then checks if the object is a object by calling . If so, then it does some more stuff to figure out what type of paint to buy. (Note to nitpickers: The actual scenario was not like this, but I presented it this way to illustrate the ...

I'm not calling a virtual function from my constructor or destructor, but I'm still getting a __purecall error

Some time ago, I described what is for: It's to detect the cases where you call a virtual method with no implementation (a so-called pure virtual method). This can happen during object constructor or destruction, since those are times when you can validly have a partially-implemented object. Well, there's another case this can happen: If ...

Psychic debugging: Why Chinese characters don't work

Here's a walkthrough of an actual case of psychic debugging. I'm using the internal XYZ table-generating tool, but it appears to be useless in my case. Does this tool work? Right now, I'm just resorting to the manual method of generating my data table (Chinese and English). Hooray for vague questions! "It appears to be useless." But there ...

Well at least nobody's parking there any more

There is a field next to the Microsoft building I used to work in, and for a time, people parked their cars out on the field, presumably because finding a proper parking space in the garage became difficult due to overcrowding. To prevent people from parking in the field, Security placed a large log across the access to the field. The ...

Dumping a hash table with external chaining from the debugger

I was doing some crash dump debugging, as I am often called upon to do, and one of the data structure I had to grovel through was something that operated basically like an atom table, so that's what I'll call it. Like an atom table, it manages a collection of strings. You can add a string to the table (getting a unique value back, which we ...