Re: lambda coding style

[Marek Polacek <polacek@redhat.com>]

On Wed, Jan 10, 2024 at 02:58:03PM -0500, Jason Merrill via Gcc wrote:
> What formatting style do we want for non-trivial lambdas in GCC sources?
> I'm thinking the most consistent choice would be
> 
> auto l = [&] (parms) // space between ] (
>   {                  // brace on new line, indented two spaces
>     return stuff;
>   };

Sure, why not.  Consistency is what matters.  Thus far we seem
to have been very inconsistent.  ;)
 
> By default, recent emacs lines up the { with the previous line, like an
> in-class function definition; I talked it into the above indentation with
> 
> (defun lambda-offset (elem)
>   (if (assq 'inline-open c-syntactic-context) '+ 0))
> (add-to-hook 'c++-mode-hook '(c-set-offset 'inlambda 'lambda-offset))
> 
> I think we probably want the same formatting for lambdas in function
> argument lists, e.g.
> 
> algorithm ([] (parms)
>   {
>     return foo;
>   });

And what about lambdas in conditions:

if (foo ()
    && [&] (params) mutable
       {
	 return 42;
       } ())

should the { go just below [?

Marek