r174504 - Optionally derive formatting information from the input file.

[Sean Silva]

> Yes, this comes up every time one argues with C++ devs :)
> There are multiple issues at play here:
> - this change only detects configuration options, it doesn't actually change
> the behavior depending on how code was formatted before in a non-canonical
> way

Ah, that's an astute observation.

> - we already configure code according to the previous whitespaces -
> obviously macros need this, but we also derive where comments belong to by
> looking at whitespace around the comment

Makes sense. Interesting.

> - applying "don't touch" to StringSwitch is a pretty strong example for the
> other end of the spectrum, and I'd strongly vote against doing this for as
> long as possible ;)

The thing about StringSwitch (at least for me) isn't "don't touch",
but rather recognize "these should be one per line".

-- Sean Silva