How to Force a C++ Class to Be a Singleton

Expertise: Intermediate
Language: C++

April 24, 2001

The following example demonstrates how to have only one instance of a class at a time.


class MySingleTon
{
public:
static MySingleTon * GetObject()
{
static MySingleTon obj;
return &obj;
}
...
//other interface functions here
...
private:
MySingleTon();
};

First, declare the constructor as private, so no one can create an instance. Next, declare a static method, like GetObject in the code above. Any client can use the only instance of the class, as shown below:


#include MySingleton.h
main()
{
MySingleTon * pObject = MySingleton::GetObject();
... use the object...
MySingleTon * pAnother = MySingleton::GetObject();

















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