On Wednesday, 4 April 2018 at 18:11:12 UTC, Jonathan M Davis
wrote:
On Wednesday, April 04, 2018 16:05:52 Timoses via
```
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;
}
```
That code doesn't compile - at least not with dmd master. It
gives these two errors:
q.d(5): Error: constructor `q.A.this` missing initializer for
immutable
field i
q.d(12): Error: cannot modify immutable expression this.i
So, it's an error that the base class doesn't initialize the
immutable member, and it's an error for the derived class to
try to assign to it.
- Jonathan M Davis
I know, should have mentioned it. The question is why, however?
A rule like the above would force all derived classes to
initialize the immutable variable from the base class (if they
were allowed to).
Why aren't they?
