BASIC "sgn" function equivalent

[pascal111]

On Thursday, 28 July 2022 at 12:13:31 UTC, Antonio wrote:
> On Thursday, 28 July 2022 at 12:02:54 UTC, pascal111 wrote:
>> I'm making an equivalent of "sgn" function of BASIC language, 
>> and I used "(T)" in its definition, but the function can 
>> receive wrong data by passing string data to it, how we can 
>> solve it?
>
>
> Use isFloating!T and isIntegral!T traits.
>
> The standard library **sng** function is a good example:
>
> https://dlang.org/library/std/math/traits/sgn.html

Of-course D has a built in "sgn" function, but I like to do it 
with my hands to be sure of code, I'm some doubtful and don't 
trust alien works.