Use macro-implemented Singleton Mode

 

I personally think it is more convenient to use

 

# Define SINGLETON_CLASS_NO_DEF_CONSTRUCT_BODY (class_name )\

Private :\

Class_name ();\

Class_name (const class_name &);\

Class_name & operator = (const class_name &);\

Public :\

Static class_name & Instance ()\

{\

Static class_name one ;\

Return one ;\

}

 

# Define SINGLETON_CLASS (class_name )\

Private :\

Class_name (){}\

Class_name (const class_name &);\

Class_name & operator = (const class_name &);\

Public :\

Static class_name & Instance ()\

{\

Static class_name one ;\

Return one ;\

}

 

The difference between two macros is only that the default no-argument constructor is implemented. Example:

 

// HostBasicInformation. h

Class HostBasicInformation

{

SINGLETON_CLASS_NO_DEF_CONSTRUCT_BODY (HostBasicInformation)

 

Public:

Virtual ~ HostBasicInformation ();

Std: string GetInstallCode ();

};

 

// HostBasicInformation. cpp

 

// If SINGLETON_CLASS is used, no parameter-free constructor needs to be defined.

HostBasicInformation: HostBasicInformation (){

 

}

 

 

 

HostBasicInformation ::~ HostBasicInformation (){

 

}

 

Std: string HostBasicInformation: GetInstallCode ()

{

Return "";

}

 

The main advantage of this macro method is that it can strictly limit the use of this type, that is, it can only be used as a singleton.

 

Std: string str_installCode = HostBasicInformation: Instance (). GetInstallCode ();