[gpvos]

I used to write

    return (0);

I.e., with a space. I'm not sure if someone ever told or recommended me to do this, but the reason I did this was consistency with other C statements, because all C statements that take some kind of expression as a parameter (if, for, while) require it to be surrounded by parentheses. So it seemed logical to me to do the same with return. I've stopped doing it now, although some of the old code still lives.

I've seen code by others where there was always a space between the function name and its arguments. That was ugly, and really confused a function call with a statement.

[krylon]

I find parens around a return value/expression slightly annoying, but not annoying enough to have a debate over it. It doesn't make the code harder to read, IMHO.

Whitespace between a function name and the arguments is significant, however, because with a function-like macro, there must be no whitespace between the name and the opening parenthesis. I've seen the following code in production code, for example:

  #include <stdlib.h>
  #define free(x) free(x), x = NULL

  free(ptr1); // Macro
  free (ptr2); // Call free(3) directly

(Whether or not such a macro is good idea is a different question entirely, the point is that you can prevent such macro-expansion by using whitespace. Aesthetically, I find it very disturbing, though.)

[rwallace]

You do need to omit whitespace between the name and the opening parenthesis when defining a functionlike macro, but it doesn't matter when you're calling it.

[krylon]

I furiously looked at the C standard (C99, anyway) and the documentation to the gcc preprocessor, and have to admit somewhat embarassedly, that you are right. The gcc preprocessor documentation clearly states:

> "If you use the macro name followed by something other than an open-parenthesis (after ignoring any spaces, tabs and comments that follow), it is not a call to the macro, and the preprocessor does not change what you have written."

Thanks for pointing this out to me!