WTF: Implement explicit RefPtr::operator bool.

WTF: Implement explicit RefPtr::operator bool.

This is the modern alternative to the "safe bool" idiom. Some changes at
call sites are required, primarily because returning a boolean does not
cause an explicit conversion.

Committed: https://crrev.com/faf124b93463720518cae3ab3eb1388f1e3b418a
Cr-Commit-Position: refs/heads/master@{#388297}

[jbroman, 2016-04-18 15:51:08]

jbroman@chromium.org changed reviewers:
+ thakis@chromium.org, yutak@chromium.org

[Yuta Kitamura, 2016-04-19 07:37:19]

lgtm

[sof, 2016-04-19 07:39:13]

sigbjornf@opera.com changed reviewers:
+ sigbjornf@opera.com

[sof, 2016-04-19 07:39:14]

Could you outline the benefits of adding explicit get()s in this context (for
one kind of smart pointer only)?

[jbroman, 2016-04-19 12:25:12]

On 2016/04/19 at 07:39:14, sigbjornf wrote:
> Could you outline the benefits of adding explicit get()s in this context (for
one kind of smart pointer only)?

The explicit conversion operator is not called in the context of returning a
bool, so some operation is needed to force the conversion. Options include
static_cast<bool>(x), bool{x}, !!x, and x.get() (since the raw pointer will
convert to bool).

This was the option preferred by reviewers in the previous CL, which converted
OwnPtr/PassOwnPtr: https://codereview.chromium.org/1878253003

[Nico, 2016-04-19 14:20:54]

lgtm

[jbroman, 2016-04-19 18:43:50]

The CQ bit was checked by jbroman@chromium.org

[commit-bot: I haz the power, 2016-04-19 18:44:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1891473002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1891473002/20001

[commit-bot: I haz the power, 2016-04-19 20:23:40]

Committed patchset #2 (id:20001)

[jbroman, 2016-04-22 17:36:17]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1912203002/ by jbroman@chromium.org.

The reason for reverting is: Possible cause of performance regressions, somehow?
https://bugs.chromium.org/p/chromium/issues/detail?id=605080.

[commit-bot: I haz the power, 2016-04-22 19:15:50]

Description was changed from

==========
WTF: Implement explicit RefPtr::operator bool.

This is the modern alternative to the "safe bool" idiom. Some changes at
call sites are required, primarily because returning a boolean does not
cause an explicit conversion.
==========

to

==========
WTF: Implement explicit RefPtr::operator bool.

This is the modern alternative to the "safe bool" idiom. Some changes at
call sites are required, primarily because returning a boolean does not
cause an explicit conversion.

Committed: https://crrev.com/faf124b93463720518cae3ab3eb1388f1e3b418a
Cr-Commit-Position: refs/heads/master@{#388297}
==========

[commit-bot: I haz the power, 2016-04-22 19:15:52]

Patchset 2 (id:??) landed as
https://crrev.com/faf124b93463720518cae3ab3eb1388f1e3b418a
Cr-Commit-Position: refs/heads/master@{#388297}