"Daniel Keep" <daniel.keep.li...@gmail.com> wrote in message
news:gmqmhk$2mb...@digitalmars.com...
>
> How do you propose to write a template implementing nullable types when
> you aren't ALLOWED to use null? You'd have to start casting around
> between integers and references, which is arguably worse than just
> supporting nullable types.
>
Devil's advocate:
---------------
struct Nullable(T)
{
private T value; // Assuming "X x;" means "X x = new X();"
private bool _isNull=true;
void set(T val) {
value = val;
_isNull = false;
}
T get() {
if (_isNull)
throw NullableTypeException("value is null")
else
return value;
}
void makeNull() {
_isNull = true;
}
bool isNull() {
return _isNull;
}
}
---------------
But admittedly, it's a kludge and vastly inferior to a nice well-implemented
"X? x;" at the language level.
