null this, classes, methods and "null this" assertion

[Steven Schveighoffer via Digitalmars-d]

On 4/10/15 9:59 PM, ketmar wrote:
> let's take a code like this:
>
> import std.stdio;
>
> class A {
>    size_t len = 42;
>    final size_t length () const { return (this !is null ? len : 0); }
> }
>
> void main () {
>    A a;
>    writeln(a.length);
>    a = new A();
>    writeln(a.length);
> }
>
> in "-release" mode this code outputs "0" and "42", as expected (by me).
> but without "-release" is raises "null this" assertion.

In non-release mode, it's calling the invariant, which is a virtual 
function.

-Steve