C++ – QFile doesn’t recognize file:/// url path format

The C++ Standard reads in section 7.3.1.1 Unnamed namespaces, paragraph 2:

The use of the static keyword is deprecated when declaring objects in a namespace scope, the unnamed-namespace provides a superior alternative.

Static only applies to names of objects, functions, and anonymous unions, not to type declarations.

Edit:

The decision to deprecate this use of the static keyword (affecting visibility of a variable declaration in a translation unit) has been reversed (ref). In this case using a static or an unnamed namespace are back to being essentially two ways of doing the exact same thing. For more discussion please see this SO question.

Unnamed namespace's still have the advantage of allowing you to define translation-unit-local types. Please see this SO question for more details.

Credit goes to Mike Percy for bringing this to my attention.

In 2008 I provided a C++98 implementation of the Singleton design pattern that is lazy-evaluated, guaranteed-destruction, not-technically-thread-safe:
Can any one provide me a sample of Singleton in c++?

Here is an updated C++11 implementation of the Singleton design pattern that is lazy-evaluated, correctly-destroyed, and thread-safe.

class S
{
    public:
        static S& 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 inaccessible(especially from outside), otherwise, you may accidentally get copies of
        // your singleton appearing.
        S(S const&);              // Don't Implement
        void operator=(S const&); // Don't implement

        // C++ 11
        // =======
        // We can use the better technique of deleting the methods
        // we don't want.
    public:
        S(S const&)               = delete;
        void operator=(S const&)  = 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
};

See this article about when to use a singleton: (not often)
Singleton: How should it be used

See this two article about initialization order and how to cope:
Static variables initialisation order
Finding C++ static initialization order problems

See this article describing lifetimes:
What is the lifetime of a static variable in a C++ function?

See this article that discusses some threading implications to singletons:
Singleton instance declared as static variable of GetInstance method, is it thread-safe?

See this article that explains why double checked locking will not work on C++:
What are all the common undefined behaviours that a C++ programmer should know about?
Dr Dobbs: C++ and The Perils of Double-Checked Locking: Part I