I just made a mistake and saw something in C, using Visual Studio 2008 C++ Express, which was so dumb (at least to my mind), that I thought it would throw a compiler error, or at least a warning, but doesn't (at least at the standard error/warning level).


// set the free block mem to a released value
memset( ((u8*)pFree) + sizeof(MemHeapFree),
MEMHEAP_RELEASED_MEM,
pFree->uSize - sizeof(sizeof(MemHeapFree)) );


See it? See the sizeof(sizeof(expression))? I just had a massive WTF moment when I saw that while stepping through the code.

So, this thread is for any other things in C, C++ or any other languages that you think other people would find strange, amusing or unbelievable.

Oh, and for anyone that's interested, the sizeof(sizeof(x)) comes out to 4, which I guess is expected once you know the compiler actually accepts it.

I think you two missed the point of the thread...

Sizeof(sizeof(x)) only evaluates to 4 on a 32-bit system. This looks like it is part of a memory management system and a pointer to the data is stored in a data structure. Doing it this way would ensure there is always enough memory allocated to store the pointer without hard-coding it. Does it make a bit more sense now?

There is nothing wrong in that code.

The author knows it's valid. It's not wrong, except for the part where it didn't do what the author intended, meaning it caused a bug (and in a memory allocator a bug is quite a wrong thing).

So, this thread is for any other things in C, C++ or any other languages that you think other people would find strange, amusing or unbelievable.

Did you all miss this part? ^^^
Too busy bikeshedding in Parkinson's committee? I heard you like bike sheds (any colour will do)...

[quote name='Antheus' timestamp='1306070656' post='4814217']There is nothing wrong in that code.

The author knows it's valid. It's not wrong, except for the part where it didn't do what the author intended, meaning it caused a bug (and in a memory allocator a bug is quite a wrong thing).

So, this thread is for any other things in C, C++ or any other languages that you think other people would find strange, amusing or unbelievable.

Did you all miss this part? ^^^
Too busy bikeshedding in Parkinson's committee? I heard you like bike sheds (any colour will do)...
[/quote]

Yes yes yes!

Guys, you are great I do appreciate the objective analysis of the code, but yes, I know it is part of a memory management system. In fact is it my own memory management system that I was fixing, in part because of a bug (not the one I posted) that was in that very function call. And I'm not looking for a static code analyzer, although I do appreciate the offer. I also completely understand why that expression returns 4 on a 32-bit system. I'm also not suggesting that this and the other million similar kinds of bugs that people write into their code every day should be picked up by the compiler, and although I immediately wondered how it had gotten past the compiler, after a half second of looking at it, I understood why it had.

As Hodgman pointed out, after the initial "What the heck?" moment, I just found this funny and was looking to add a bit more humor to the forum. So, please, whatever you've got, I'd definitely like to see, in whatever language or form that you feel like sharing it in.

In that case, I consider the functions sprintf, strcpy, strcmp etc without a length parameter to be some of the silliest features of C :-) the fact that nobody considered it to ever be a security problem, and that so many programs use these functions in network code and other security sensitive code without a second thought... Now that is daft indeed :-) (yeah, modern compilers sometimes warn about unsafe functions such as these but jees, it took them how many decades to realise?)

In that case, I consider the functions sprintf, strcpy, strcmp etc without a length parameter to be some of the silliest features of C :-) the fact that nobody considered it to ever be a security problem, and that so many programs use these functions in network code and other security sensitive code without a second thought... Now that is daft indeed :-) (yeah, modern compilers sometimes warn about unsafe functions such as these but jees, it took them how many decades to realise?)

I agree, that was kinda strange.

Come on guys and gals, surely more people have something they wish to share with the rest of the class?