"inline" conversion of array to immutable

[FreeSlave via Digitalmars-d-learn]

On Friday, 22 April 2016 at 11:07:47 UTC, Jeff Thompson wrote:
> On Friday, 22 April 2016 at 09:40:14 UTC, FreeSlave wrote:
>> On Friday, 22 April 2016 at 09:25:32 UTC, Jeff Thompson wrote:
>>> Hello. The following code compiles OK where func creates a 
>>> mutable array and main assigns it to an immutable variable:
>>>
>>> [...]
>>
>> Probably this is what you look for 
>> http://dlang.org/phobos/std_exception.html#.assumeUnique
>
> OK, we lose the compiler check for correctness. What if I put 
> func directly in main with the hopes that the compiler will 
> check correctness and also inline the function? But it won't 
> assign to the immutable array. Why not? It's the same function.
>
> void main(string[] args) {
>   int[] func(int x) pure {
>     int[] result = new int[10];
>     result[0] = x;
>     return result;
>   }
>   immutable int[] array = func(1);
> }

Not sure why, but making func static fixes this:

void main(string[] args) {
   static int[] func(int x) pure {
     int[] result = new int[10];
     result[0] = x;
     return result;
   }
   immutable int[] array = func(1);
}