A very simple base class:
class Figure {
public List<?> getList() {
var list = new List<same as child>();
//do some code
//filling list
return list;
}
}
This inheriting class:
class Rectangle : Figure
{
}
class Cube : Figure
{
}
I know I could use the generic like this:
class Figure {
public List<T> getList<T>() {
var list = new List<T>();
//do some code
//filling list
return list;
}
}
Rectangle rec = new Rectangle();
List<Rectangle> lRec = rec.getList<Rectangle>();
Cube cube = new Cube();
List<Cube> lCube = cube.getList<Cube>();
But I want to know if there is an alternative
Like this:
Rectangle rec = new Rectangle();
List<Rectangle> lRec = rec.getList();
Cube cube = new Cube();
List<Cube> lCube = cube.getList();
CodePudding user response:
If you constraint the type parameter to the implementing class you get what you're looking for:
class Figure<T> where T : Figure<T>
{
public List<T> getList()
{
var list = new List<T> ();
//do some code
//filling list
return list;
}
}
class Rectangle : Figure<Rectangle>
{
}
class Cube : Figure<Cube>
{
}
Depending on the scenario marking getList
as virtual or abstract might come in handy