Re: abs and minimum values

[kyle via Digitalmars-d-learn]

On Friday, 29 October 2021 at 18:19:58 UTC, Salih Dincer wrote:

On Thursday, 28 October 2021 at 21:23:15 UTC, kyle wrote:

```
void main()
{
    import std.math : abs, sgn;

    alias n_type = short; //or int, long, byte, whatever

    assert(n_type.min == abs(n_type.min));
    assert(sgn(abs(n_type.min)) == -1);
}
```

I stumbled into this fun today. I understand why abs yields a negative value here with overflow and no promotion. I just want to know if it should. Should abs ever return a negative number? Thanks.

this should work on all types:
```d
auto sign(T)(T n) {
  return abs(n) / n;
}
```

Surprisingly, no.
sign(short.min) == 1