我可以在这里使用模板吗？

Question

I have the following piece of code:

int CreatePropertiesDialog(int type, void *object)
{
    if( type == 1 )
    {
        ClassA *a = static_cast<ClassA *>( object );
        // build the properties dialog
    }
    if( type == 2 )
    {
        ClassB *b = static_cast<ClassB *>( object );
        // build the properties dialog
    }
    // display the properties dialog
}

However, the use of void* type sounds very ugly.

Can this code be improved by using template? Or maybe some other means?

Answer 1

You can ditch the type parameter altoghether and have two methods, one for ClassA or one for ClassB . Like this:

int CreatePropertiesDialog(ClassA *a)
{
        // build the properties dialog
        DialogConf conf = ...
        return displayDialog(conf);   
}


int CreatePropertiesDialog(ClassB *b)
{
        // build the properties dialog
        DialogConf conf = ...
        return displayDialog(conf);   
}

int displayDialog(DialogConf conf) {
    // ...
}

Or, you can have ClassA and ClassB responsible for building the configuration by each having a method that returns a DialogConf that contains the configuration and then pass it to displayDialog .

Answer 2

Depends on how you call the code and what is the available data.

For example, if you have a bunchof void* :

void** objects = get_objects();

CreatePropertiesDialog(type, objects[1]);

Then your input is all void* . Must must process it as is or refactor the code to not use void pointers.

If you have locals or variables of known types, then overloading might be appropriated:

int CreatePropertiesDialog(ClassA*) {
    // ...
}

int CreatePropertiesDialog(ClassB*) {
    // ...
}

Without more information about what you have as input data it's hard to have a more precise answer.