905243 - make mozilla::Atomic constructors constexpr

Status: RESOLVED FIXED

(Core :: MFBT, defect)

Comment 1

[Nathan Froyd [:froydnj]]

Attachment: make mozilla::Atomic constructors constexpr

People often use Atomic<T> as top-level global variables.  Such uses generate
static constructors for some compilers.  This seems undesirable, and contrary
to <atomic>, where std::atomic::atomic(T) is already constexpr, and the no-arg
constructor is |= default|.  We can do roughly the same thing in our wrapper
(though we don't have |= default|), and we should, to be efficient.

Comment 2

[Trevor Saunders (:tbsaunde)]

Attachment: bug 905243 - make the constructors for mozilla::Atomic constexpr

Comment 3

[Nathan Froyd [:froydnj]]

Comment on attachment 790419 [details] [diff] [review]
bug 905243 - make the constructors for mozilla::Atomic constexpr

Review of attachment 790419 [details] [diff] [review]:
-----------------------------------------------------------------

r=me if you:

- add #include "mozilla/Attributes.h" for MOZ_CONSTEXPR;
- add the appropriate MOZ_CONSTEXPR bits for the IsEnum specialization also.

Comment 4

[Nathan Froyd [:froydnj]]

Comment on attachment 790307 [details] [diff] [review]
make mozilla::Atomic constructors constexpr

Trevor has virtually the same patch.

Comment 5

[Trevor Saunders (:tbsaunde)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/83ba61bc9500

Comment 7

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/83ba61bc9500