Yes, it will work, if and only if the base class destructor is virtual, which you have done for the Base base class but not for the IFoo base class. If the base class destructor is virtual, then when you call operator delete on the base class pointer, it uses dynamic dispatch to figure out … Read more
If your constant is describing your object, then it should be a property. A constant, by its name, should not change and was designed to be unaffected by polymorphism. The same apply for static variable. You can create an abstract property (or virtual if you want a default value) in your base class: public abstract … Read more
In class bar, add using foo::a; This is a common ‘gotcha’ in C++. Once a name match is found in the a class scope, it doesn’t look further up the inheritance tree for overloads. By specifying the ‘using’ declaration, you bring all of the overloads of ‘a’ from ‘foo’ into the scope of ‘bar’. Then … Read more
There are 2 easy ways – one below, other one in @lukasgeiter’s answer as proposed by Taylor Otwell, which I definitely suggest checking as well: // app/config/app.php or anywhere you like ‘aliases’ => [ … ‘MorphOrder’ => ‘Some\Namespace\Order’, ‘MorphStaff’ => ‘Maybe\Another\Namespace\Staff’, … ] // Staff model protected $morphClass=”MorphStaff”; // Order model protected $morphClass=”MorphOrder”; done: $photo … Read more
@JsonSubTypes.Type must have a value and a name like this, @JsonTypeInfo(use=JsonTypeInfo.Id.NAME, include=As.WRAPPER_OBJECT, property=”type”) @JsonSubTypes({ @JsonSubTypes.Type(value=Dog.class, name=”dog”), @JsonSubTypes.Type(value=Cat.class, name=”cat”) }) In the subclass, use @JsonTypeName(“dog”) to say the name. The values dog and cat will be set in the property named type.
You can absolutely use specific return types, even though most examples on the web seems to return the ActionResult. The only time I would return the ActionResult class is when different paths of the action method returns different subtypes. Steven Sanderson also recommends returning specific types in his book Pro ASP.NET MVC Framework. Take a … Read more
This means that the type parameter must support comparison with other instances of its own type, via the Comparable interface. An example of such a class is provided in the Oracle tutorial Object Ordering. Note the similar pattern to T extends Comparable<T> in the excerpt below: public class Name implements Comparable<Name> { … public int … Read more
When writing the __init__ function for a class in python, you should always call the __init__ function of its superclass. We can use this to pass the relevant attributes directly to the superclass, so your code would look like this: class Person(object): def __init__(self, name, phone): self.name = name self.phone = phone class Teenager(Person): def … Read more
Since I obviously opt for option 1 (:-)) let me try to elaborate it a little more so that it is less breakable and avoid hardcoding concrete instances into the model binder. The idea is to pass the concrete type into a hidden field and use reflection to instantiate the concrete type. Suppose that you … Read more
Yes, it would. And why should it not? Because child is in fact an instance of Parent. If, you want to perform an operation only for a child you should check if (child instanceof Child){ } However you should remember the following statement from Effective C++, by Scott Meyers : “Anytime you find yourself writing … Read more