1248784 - Allow RefPtr to operate on arbitrary pointers with RefPtrTraits

Status: RESOLVED FIXED

Description

[Bobby Holley (:bholley)]

Per discussion on IRC. This will be useful for our opaque pointers to reference-counted Servo types.

I have working patches, uploading momentarily.

Comment 1

[Bobby Holley (:bholley)]

Created attachment 8719993 [details] [diff] [review]
Part 1 - Rename the existing AddRefTraits to ConstRemovingRefPtrTraits. v1

Comment 2

[Bobby Holley (:bholley)]

Created attachment 8719994 [details] [diff] [review]
Part 2 - Extract the AddRef/Release calls into a non-inner helper trait. v1

Comment 3

[Bobby Holley (:bholley)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=9fb2814e1d3e

Comment 4

[Nathan Froyd [:froydnj]]

Comment on attachment 8719994 [details] [diff] [review]
Part 2 - Extract the AddRef/Release calls into a non-inner helper trait. v1

Review of attachment 8719994 [details] [diff] [review]:
-----------------------------------------------------------------

r=me with some additional documentation.

::: mfbt/RefPtr.h
@@ +20,5 @@
>  namespace mozilla {
>  template<class T> class OwningNonNull;
> +
> +template<class U>
> +struct RefPtrTraits

Could you please write a bit of documentation here?  Seomthing about how the canonical way to refcount with RefPtr is to use AddRef and Release methods, but if you have a pointer type that has differently-named methods, you can use specializations of RefPtrTraits to call those methods instead?

Please also document that U should not be a |const|-qualified type, or add a static_assert to verify !IsConst<U>::value.

Comment 5

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/c9431b91f570
https://hg.mozilla.org/integration/mozilla-inbound/rev/5039eb1fa76c

Comment 6

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/b8231765b22c

Comment 7

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/c9431b91f570
https://hg.mozilla.org/mozilla-central/rev/5039eb1fa76c
https://hg.mozilla.org/mozilla-central/rev/b8231765b22c