Non-null objects, the Null Object pattern, and T.init

[Walter Bright]

On 1/17/2014 12:35 PM, "Ola Fosheim Grøstad" 
<ola.fosheim.grostad+dlang at gmail.com>" wrote:
> On Friday, 17 January 2014 at 19:43:58 UTC, Walter Bright wrote:
>> I've almost never had a problem tracking down the cause of a null pointer.
>> Usually just a few minutes with a debugger and getting a backtrace.
>
> Doesn't work if the unexpected "null" sits in a graph and the source of it is
> hard to pinpoint or occurs "randomly". E.g. if you are using a "black box"
> framework or it happens spuriously on a server because it is triggered by a
> database timeout which never happens on the dev server.

As I replied elsewhere, tracking down the source of a bad value in any variable 
is a standard debugging problem. There isn't anything special about null in this 
regard.