Can Singleton Design Patterns Return References Instead of Pointers?

Can Singleton Design Patterns Return References Instead of Pointers?

The conventional approach in C for creating a singleton involves returning a pointer to the instantiated object. However, an alternative technique is proposed: returning a reference instead.

This approach appears logical as it eliminates the responsibility of manually freeing the singleton object. The reason for this lies in the difficulty of determining who maintains a reference to the singleton, making it unwise to attempt manual deallocation.

Employing a static function method achieves both lazy initialization and ensures that the object is created and destroyed only once:

<code class="cpp">class S
{
    public:
        static S& getInstance()
        {
            static S    instance;
            return instance;
        }
    private:
        S() {}
        S(S const&);              // Don't Implement.
        void operator=(S const&); // Don't implement
 };</code>

Additionally, the constructor must be made private and the default copy constructor and assignment operator must be overridden to prevent copying and thus maintaining the singleton property.

However, it is crucial to note that this technique may not provide thread safety in all scenarios. In such cases, consider the following resources:

• https://stackoverflow.com/a/1008289/14065
• Singleton: How should it be used
• C Singleton design pattern

Remember to carefully evaluate the reasons for utilizing a singleton to ensure it is the appropriate design choice.

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