Fun with C

[jgrafton]

A fun way to make your C (C99, really) code slightly less readable:

If you need to make a multiline comment, you would typically either use the /* */ comment style or prefix each line with //, as newly defined in the C99 standard.

For example,

/* This is
   some longer comment
*/

// This is also
// a multiline comment

But the more fun way is to use a combination of the newer //-style comment combined with \.

For example:

// This is also a \
   multiline comment \
   though much less obviously \
   so

If you use gcc with -Wall it'll complain at you, but otherwise it works perfectly fine. Yay C!

(I happened to discover this by accident when I ended a //-style comment with a :\ smiley and suddenly things broke.)

Comments

[twizmer.livejournal.com]

Point 1: Wait, everybody doesn't already know about using \ to extend lines?
Point 2: Is that really less readable?
Point 3: Real men comment C code with #if 0

[jgrafton]

It was more that I expected the comment to gobble up the \ instead of letting the comment continue to the next line.

It's not necessarily less readable, but it can make code confusing, especially if you're dumb and not using a syntax-highlighting editor (or the one you're using is broken).

[physics-dude.livejournal.com]

From what Wikipedia says is the current C99 spec:

"Except within a character constant, a string literal, or a comment, the characters // introduce a comment that includes all multibyte characters up to, but not including, the next new-line character. The contents of such a comment are examined only to identify multibyte characters and to find the terminating new-line character." (page 78)

Bad gcc. No biscuit.

[brpxqzme.livejournal.com]

By golly, -pedantic doesn't spit any errors!

// Now that's a comment that deserves an =O

[jgrafton]

well, as I said, gcc complains with -Wall, at least.

[brpxqzme.livejournal.com]

I meant -pedantic -std=c99

GNU standards allow // comments in normal ol' C code, for example. You gotta say -ansi or -std=c99 to really say it's non-standard. The point still stands though... then again, I bet some people who put messages in ./configure scripts that make out to something like "GCC WILL DESTROY ALL FOREIGN CC". Nice find.

[chrisamaphone]

Aw, I'm sorry your code was depressing enough to merit a :\.