short s, t; t = -s: no (longer) works: Deprecation: integral promotion not done for -s, use

[kdevel]

On Saturday, 24 February 2018 at 20:17:12 UTC, Steven 
Schveighoffer wrote:
> On 2/24/18 3:07 PM, kdevel wrote:
>> I don't get the point of the deprecation message:
>> 
>> --- intprom.d
>> import std.stdio;
>> 
>> void main ()
>> {
>>     short s, t;
>>     t = -s;
>> }
>> ---
>
> https://dlang.org/changelog/2.078.0.html#fix16997

My goodness! So there is currently no negation operator defined 
on short and some other types?

>> $ dmd intprom.d
>> intprom.d(6): Deprecation: integral promotion not done for -s, 
>> use '-transition=intpromote' switch or -cast(int)(s)
>> 
>> What shall I do in order to get my template code
>> 
>> void mymain (T) ()
>> {
>>     :
>>        b[i] = -b [i];
>>     :
>> }
>> 
>> compiled for any type for which negation is defined?
>
> b[i] = cast(typeof(b[i]))-b[i];
>
> And then use -transition=intpromote.
>
> Note, your function wasn't real code, so maybe if you have the 
> type of b[i] somewhere it might look better than what I wrote 
> (like maybe cast(T)-b[i]).

Any objections against leaving out the compiler switch and using

    b[i] = cast (T) (0 - b[i]);

instead?