Thread-safe singleton

[sabrog]

I would like to hear your criticism about "this":http://developer.qt.nokia.com/wiki/Qt_thread-safe_singleton article.

[lyuts]

I think that
@static T& instance()@

should become
@static const T& instance()@

UPD: And i think that you need to explain in that article what do you need call_once for, since this is a wiki page.

[sabrog]

Why reference to T must be const, what if user want change internal state of class?

call_once it's thread-safe alternative for Double-Checked Locking pattern.

[lyuts]

[quote author="SABROG" date="1282146241"]Why reference to T must be const, what if user want change internal state of class?[/quote]

Yep, you are right. My fault.

[quote author="SABROG" date="1282146241"]call_once it's thread-safe alternative for Double-Checked Locking pattern.[/quote]

I read about it :). What I meant is towrite just a few words of description on that page, so there is not just naked code.