On Friday, 20 February 2015 at 08:25:49 UTC, rumbu wrote:
On Friday, 20 February 2015 at 07:57:17 UTC, Tobias Pankrath
wrote:
What's the reason behind this design?
class Super {}
class Sub : Super {}
void foo(Super[] sup) {}
void main() {
Sub[] array;
foo(array); // error, cannot call foo(Super[]) with
arguments (Sub[])
}
Just make the sup parameter const:
void foo(in Super[] sup) {}
http://dlang.org/arrays.html (end of the page):
A dynamic array T[] can be implicitly converted to one of the
following:
const(U)[]
const(U[])
Where U is a base class of T.
The reson behind the design - I wonder about that also.
Thanks, didn't know that. Makes sense.
Probably the reason is:
void foo(Super[] sup) { sup[3] = new AnotherDerivedClass(); }
After foo returns the slice passed as argument would violate its
invariant.
