if( foo( 5, 6, 7 )) do_something( arr[ 5 ]);
if more readable than:
if (foo(5, 6, 7)) do_something(arr)
yet very few people use whitespace inside their parens. The venerable indent program doesn't really provide useful options for this behavior (the option to include whitespace inside parens adds a space between consecutive occurrences, which is pretty hideous), and certainly some people will argue that it's a waste of horizontal space (but those same people would probably omit the spaces after the comma as well, so their opinion is clearly suspect), but surely there's some valid reason that this style is not more popular.
Why don't you use any whitespace inside your parentheses and/or braces?