[cmake-developers] A policy for Policies

[Brad King]

On 06/09/2015 11:24 AM, David Cole wrote:
> Is there a single example of a policy wherein the OLD behavior has
> actually been removed?

No.  This thread is about starting plans to actually remove some.

> It would good for all of us to understand exactly what it looks like
> to remove an OLD behavior.

>From the user perspective it means that it is an error for a project
to not set the policy to NEW before hitting a relevant case.

Typically cmake_minimum_required sets old policies to NEW implicitly.
Older projects that do not have a sufficiently high requirement may
no longer build.  Perhaps instead we should make it an error only
to explicitly set the policy to OLD and leave it as a warning to
not set it to NEW.

Either way the implementation of the OLD behavior will be removed
and the NEW behavior will always be used.

-Brad