On Wednesday, 4 April 2018 at 10:41:52 UTC, Simen Kjærås wrote:
Because by the time B's constructor is called, A might already
have initialized it, and rely on it never changing.
What about:
```
class A
{
immutable int i;
this(){}
}
class B : A
{
this()
{
this.i = 3;
super(); // <- specifically calling
// super constructor afterwards
}
}
void main()
{
auto b = new B;
}
```
Same result
The solution is to add a constructor overload to A, and call
that from B:
class A
{
immutable int i;
protected this(int i) {
this.i = i;
}
}
class B : A
{
this()
{
super(3);
}
}
unittest
{
auto b = new B;
}
--
Simen
This becomes a bit hideous, unfortunately, when there are many
initializations involved.
Found this, but it doesn't mention anything about derived
classes..
https://dlang.org/spec/class.html#field-init
