1315624 - Delete operator|| and operator&& for CastableTypedEnumResult

Status: RESOLVED FIXED

(Core :: MFBT, defect)

Description

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

We should delete operator|| and operator&& for CastableTypedEnumResult [1]. Defining these two operators destroy short-circuit evaluation. This leads to a real assert in [2] where PropHasFlags() is evaluated even if (aEnabled & EnabledState::eInUASheets) is false when "layout.css.prefixes.webkit" is set to false on Nightly.

BTW, "More Effective C++ Item 7" recommended never overloading these two operator as well. 

[1] http://searchfox.org/mozilla-central/rev/f5c9e9a249637c9abd88754c8963ecb3838475cb/mfbt/TypedEnumBits.h#89-90
[2] http://searchfox.org/mozilla-central/rev/f5c9e9a249637c9abd88754c8963ecb3838475cb/layout/style/nsCSSProps.h#659

Comment 1

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Attachment: Bug 1315624 - Delete operator&& and operator|| for CastableTypedEnumResult.

Defining these two function destroy short-circuit evaluation.

Review commit: https://reviewboard.mozilla.org/r/91022/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/91022/

Comment 2

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=b9e6d09bbcf6

Comment 3

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Comment on attachment 8808092 [details]
Bug 1315624 - Delete operator&& and operator|| for CastableTypedEnumResult.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/91022/diff/1-2/

Comment 4

[Nathan Froyd [:froydnj]]

Comment on attachment 8808092 [details]
Bug 1315624 - Delete operator&& and operator|| for CastableTypedEnumResult.

https://reviewboard.mozilla.org/r/91022/#review92810

Thank you for writing tests!

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0dfe466e790f
Delete operator&& and operator|| for CastableTypedEnumResult. r=froydnj

Comment 6

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/0dfe466e790f