cc-mode indent, exception for long lines

[Matt Armstrong]

I like to keep my C code lines to 80 columns, for easier
editing/printing.

But, sometimes I have a long string constant or identifier, and
cc-mode's indentation isn't optimal.  E.g.

    if (ReallyLongFunctionName(AnotherReallyLongFunctionName("a really long 
string constant") 
    {
    }

I haven't been able to get cc-mode to help me much here.  It'd be great
if it had a way to sense that the result of an indentation will go
beyond N columns and go into an alternate mode that results in something
like this:

    if (ReallyLongFunctionName(
                AnotherReallyLongFunctionName(
                    "a really long string constant") 
    {
    }

(the above indentation is the "vim" editor's default indentation -- the
first line after a paren is indented 8 spaces, all subsequent lines 8+4
spaces).

Any tips?

-- 
matt