Wouldn't it be nice to have a type variable referring to the class's instance.
- by user93197
I often have a pattern like this:
class VectorBase<SubClass, Element>
where SubClass : VectorBase<SubClass, Element>, new()
where Element : Addable<Element>
{
Element[] data;
public VectorBase(Element[] data)
{
this.data = data;
}
public SubClass add(SubClass second)
{
Element[] newData = new Element[data.Length];
for (int i = 0; i < newData.Length; i++)
{
newData[i] = data[i].add(second.data[i]);
}
SubClass result = new SubClass();
result.data = newData;
return result;
}
}
class VectorInt : VectorBase<VectorInt, Int32>
{
}
class MyInt : Addable<MyInt>
{
int data;
public MyInt(int data)
{
this.data = data;
}
public MyInt add(MyInt t)
{
return new MyInt(data + t.data);
}
}
interface Addable<T>
{
T add(T t);
}
But I would rather just have:
class VectorBase2<Element> where Element : Addable<Element>
{
Element[] data;
public VectorBase(Element[] data)
{
this.data = data;
}
public SubClass add(SubClass second)
{
Element[] newData = new Element[data.Length];
for (int i = 0; i < newData.Length; i++)
{
newData[i] = data[i].add(second.data[i]);
}
SubClass result = new SubClass(data);
return result;
}
}
class VectorInt2 : VectorBase2<Int32>
{
}
Why not make the subclass type available to all classes? Is this technically impossible?
