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    <p>See this article for a simple design for a lazy evaluated with guaranteed destruction singleton:<br> <a href="https://stackoverflow.com/questions/270947/can-any-one-provide-me-a-sample-of-singleton-in-c/271104#271104">Can any one provide me a sample of Singleton in c++?</a> </p> <p>The classic lazy evaluated and correctly destroyed singleton.</p> <pre><code>class S { public: static S&amp; getInstance() { static S instance; // Guaranteed to be destroyed. // Instantiated on first use. return instance; } private: S() {} // Constructor? (the {} brackets) are needed here. // C++ 03 // ======== // Don't forget to declare these two. You want to make sure they // are unacceptable otherwise you may accidentally get copies of // your singleton appearing. S(S const&amp;); // Don't Implement void operator=(S const&amp;); // Don't implement // C++ 11 // ======= // We can use the better technique of deleting the methods // we don't want. public: S(S const&amp;) = delete; void operator=(S const&amp;) = delete; // Note: Scott Meyers mentions in his Effective Modern // C++ book, that deleted functions should generally // be public as it results in better error messages // due to the compilers behavior to check accessibility // before deleted status }; </code></pre> <p>See this article about when to use a singleton: (not often)<br> <a href="https://stackoverflow.com/questions/86582/singleton-how-should-it-be-used">Singleton: How should it be used</a></p> <p>See this two article about initialization order and how to cope:<br> <a href="https://stackoverflow.com/questions/211237/c-static-variables-initialisation-order/211307#211307">Static variables initialisation order</a><br> <a href="https://stackoverflow.com/questions/335369/finding-c-static-initialization-order-problems/335746#335746">Finding C++ static initialization order problems</a> </p> <p>See this article describing lifetimes:<br> <a href="https://stackoverflow.com/questions/246564/what-is-the-lifetime-of-a-static-variable-in-a-c-function">What is the lifetime of a static variable in a C++ function?</a> </p> <p>See this article that discusses some threading implications to singletons:<br> <a href="https://stackoverflow.com/questions/449436/singleton-instance-declared-as-static-variable-of-getinstance-method/449823#449823">Singleton instance declared as static variable of GetInstance method</a></p> <p>See this article that explains why double checked locking will not work on C++:<br> <a href="https://stackoverflow.com/questions/367633/what-are-all-the-common-undefined-behaviour-that-c-programmer-should-know-about/367690#367690">What are all the common undefined behaviours that a C++ programmer should know about?</a><br> <a href="http://www.drdobbs.com/cpp/c-and-the-perils-of-double-checked-locki/184405726" rel="noreferrer">Dr Dobbs: C++ and The Perils of Double-Checked Locking: Part I</a></p>
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    1. CO@fnieto: Thanks. What I was trying to imply with the constructor S() should be declared private. As singeltons will have other members (otherwise why have a singelton) that need to be initialized (note there is __not__ a Don't implement), so when you do declarea a constructor it will need to be private.
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    2. COGood answer. But should note that this is not thread-safe http://stackoverflow.com/questions/1661529/is-meyers-implementation-of-singleton-pattern-thread-safe
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    3. COAlready noted above in: http://stackoverflow.com/questions/449436/singleton-instance-declared-as-static-variable-of-getinstance-method/449823#449823
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