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    <p>You are correct that static initialization like that isn't thread safe (<a href="http://www.tilander.org/aurora2/Static_initialization_in_Cpp/index.html" rel="nofollow noreferrer">here</a> is an article discussing what the compiler will turn it into)</p> <p>At the moment, there's no standard, thread safe, portable way to initialize static singletons. Double checked locking can be used, but you need potentially non-portable threading libraries (see a discussion <a href="http://www.devarticles.com/c/a/Cplusplus/C-plus-in-Theory-Why-the-Double-Check-Lock-Pattern-Isnt-100-ThreadSafe/3/" rel="nofollow noreferrer">here</a>).</p> <p>Here's a few options if thread safety is a must:</p> <ol> <li>Don't be Lazy (loaded): Initialize during static initialization. It could be a problem if another static calls this function in it's constructor, since the order of static initialization is undefined(see <a href="https://isocpp.org/wiki/faq/ctors#static-init-order" rel="nofollow noreferrer">here</a>).</li> <li>Use boost (as you said) or Loki</li> <li>Roll your own singleton on your supported platforms (should probably be avoided unless you are a threading expert)</li> <li>Lock a mutex everytime you need access. This could be very slow.</li> </ol> <p>Example for 1:</p> <pre><code>// in a cpp: namespace { Dog dog("Lassie"); } Dog* MyClass::BadMethod() { return &amp;dog; } </code></pre> <p>Example for 4:</p> <pre><code>Dog* MyClass::BadMethod() { static scoped_ptr&lt;Dog&gt; pdog; { Lock l(Mutex); if(!pdog.get()) pdog.reset(new Dog("Lassie")); } return pdog.get(); } </code></pre>
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    1. USTodd Gardner
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    1. COI ended up biting the bullet and using `boost::call_once()`
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    2. COthis answer is now obsolete: http://stackoverflow.com/questions/8102125/is-local-static-variable-initialization-thread-safe-in-c11
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