BASIC "sgn" function equivalent

[pascal111]

On Thursday, 28 July 2022 at 15:38:18 UTC, H. S. Teoh wrote:
> On Thu, Jul 28, 2022 at 03:10:19PM +0000, pascal111 via 
> Digitalmars-d-learn wrote:
>> > [...]
> [...]
>> [...]
>
> AFAIK, all D compilers ship with full Phobos source code. On my 
> installation, it's in 
> /usr/lib/gcc/x86_64-linux-gnu/11/include/d/*. You can probably 
> find yours in a similar (or the same) location. Under that 
> directory, just look into std/math/*.d for the std.math 
> functions. For example, .sgn is in std/math/traits.d.
>
> In general, all 3 D compilers ship with the same Phobos 
> sources, except perhaps in a few places where some 
> compiler-specific fixes were needed. Generally, though, I think 
> the idea is to merge all such changes upstream under version() 
> blocks so that we can use the same Phobos sources for all 
> compilers.
>
>
> T

I checked this path 
"/usr/lib/gcc/x86_64-linux-gnu/11/include/d/*" yesterday in my 
Ubuntu. I think you are right. Thanks!