What is the proper way to outline static-if-conditions ?

[drug]

You just need to check if T is a pointer:
```D
import std;

alias DA = int[];
alias SA = int[3];

alias PSA = SA*;
alias PDA = DA*;

version(all)
	enum isPointedStaticArray(T) = isPointer!T && 
isStaticArray!(PointerTarget!T);
else
	enum isPointedStaticArray(T) = isPointer!T && is(PointerTarget!T : 
P[N], P, size_t N);  // this way you can get array length

static assert(!isPointedStaticArray!DA);
static assert(!isPointedStaticArray!SA);
static assert(!isPointedStaticArray!PDA);
static assert( isPointedStaticArray!PSA);

void main()
{
}
```
https://run.dlang.io/is/qKdx1D

Also you can use another way to detect static array - it can be useful 
if you need to get its length