c-lineup-arglist-operators is a compiled Lisp function in `cc-align.el'.

(c-lineup-arglist-operators LANGELEM)

Line up lines starting with an infix operator under the open paren.
Return nil on lines that don't start with an operator, to leave those
cases to other line-up functions. Example:

if ( x < 10
|| at_limit (x, <- c-lineup-arglist-operators
list) <- c-lineup-arglist-operators returns nil

Since this function doesn't do anything for lines without an infix
operator you typically want to use it together with some other line-up
settings, e.g. as follows (the arglist-close setting is just a
suggestion to get a consistent style):

(c-set-offset 'arglist-cont '(c-lineup-arglist-operators 0))
(c-set-offset 'arglist-cont-nonempty '(c-lineup-arglist-operators
(c-set-offset 'arglist-close '(c-lineup-arglist-close-under-paren))

Works with: arglist-cont, arglist-cont-nonempty.