On 07/25/2016 05:47 PM, Adam D. Ruppe wrote:
> On Monday, 25 July 2016 at 13:09:22 UTC, Bahman Movaqar wrote:
>> From what I could gather, it's not possible to check for `null` at
>> runtime for reference based types. Am I right?
>
> No, it is only possible to check for null for reference based
On Monday, 25 July 2016 at 13:09:22 UTC, Bahman Movaqar wrote:
From what I could gather, it's not possible to check for `null`
at
runtime for reference based types. Am I right?
No, it is only possible to check for null for reference based
types. But map's result is not a reference based
On 07/25/2016 05:07 PM, Bahman Movaqar wrote:
> Suppose I have the following function:
>
> public auto max(alias comp, Range)(Range r)
> in {
> assert(r !is null && !r.empty);
> }
> body {
> // ...
> }
>
> When the function after a series of chained `map`
On Monday, 25 July 2016 at 12:37:18 UTC, Bahman Movaqar wrote:
Suppose I have the following function:
public auto max(alias comp, Range)(Range r)
in {
assert(r !is null && !r.empty);
}
body {
// ...
}
When the function after a series of chained `map` operations,
On Monday, 25 July 2016 at 12:47:25 UTC, Cauterite wrote:
(!__traits(compiles, r is null) || r !is null) && !r.empty
Ah, whoops that's wrong, looks like ketmar had the right idea.
On Monday, 25 July 2016 at 12:37:18 UTC, Bahman Movaqar wrote:
But I'm curious; how can I check for a
`null` in this case?
Well, if you're happy with assertion failure by access violation,
you may not even need to check for null, because generally if you
try to call .empty on a null pointer
On Monday, 25 July 2016 at 12:37:18 UTC, Bahman Movaqar wrote:
Error: incompatible types for ((r) !is (null)):
'MapResult!(__lambda2, SInvoiceLine[])' and 'typeof(null)'
Of course if I remove `r !is null` from the `in` block,
everything will work. But I'm curious; how can I check for a
static if (is(typeof(r is null))) { ...you can do your assert
here... }
Suppose I have the following function:
public auto max(alias comp, Range)(Range r)
in {
assert(r !is null && !r.empty);
}
body {
// ...
}
When the function after a series of chained `map` operations, I get the
following error:
Error: incompatible types for
