Re: Distinguish between a null array and an empty array

[Steven Schveighoffer via Digitalmars-d-learn]

On 5/24/20 8:12 AM, bauss wrote:

Is there a way to do that?

Since the following are both true:

int[] a = null;
int[] b = [];

assert(a is null);
assert(!a.length);

assert(b is null);
assert(!b.length);

What I would like is to tell that b is an empty array and a is a null array.

The issue is simply that [] is the same as null.

Try this:

T[] emptyArr(T)() @trusted
{
   T* p = null;
   return p[1 .. 1];
}


int[] b = emptyArr!int;

assert(b !is null);
assert(!b.length);

-Steve