Possible Duplicate:
How to force a static member to be initialized?
How to automatically register a class on creation
I have a class which should register her create method in a Factory such that I can create this class by using the factory. However the initialisation only works if I instantiate the class in the main method.
Here the class which I want to register:
class CDESolverD2Q5 : public CDESolver
{
public:
static CDESolver* create()
{
return new CDESolverD2Q5;
}
private:
static const std::string name_;
/**
* @brief registered_ if true then class is registered w/ Solver Factory
*/
//only for accessing this element from the main method
public:
static const bool registered_;
/**
* @brief registerLoader Registers the Solver with the factory.
* @return A boolean that indicates if the registration was successful
*/
static bool registerLoader();
};
And here the code in the cpp file:
const std::string CDESolverD2Q5::name_ = "CDESolverD2Q5";
bool CDESolverD2Q5::registerLoader()
{
return SolverFactory.registerType(CDESolverD2Q5::name_, CDESolverD2Q5::create);
}
const bool CDESolverD2Q5::registered_ = CDESolverD2Q5::registerLoader();
And here the registerType method of my factory:
bool registerType(const IdentifierType& id,
ProductCreatorSignature creator)
{
return productMap_.insert(typename ProductMap::value_type(id, creator)).second;
}
However the static member is only initialised if I access it in the main method:
int main(int argc, char* argv[]) {
//how can I avoid the next line?
bool blub = CDESolverD2Q5::registered_;
CdeSolver* solver =SolverFactory.createObject("CDESolverD2Q5");
}
If I remove the line bool blub = CDESolverD2Q5::registered_; The class is not registered in my factory. But I thought that static members a initialised automatically before the main method is executed, then why do I need this line and how could I avoid this line?
