BASIC "sgn" function equivalent

[H. S. Teoh]

On Thu, Jul 28, 2022 at 03:10:19PM +0000, pascal111 via Digitalmars-d-learn wrote:
> On Thursday, 28 July 2022 at 15:03:34 UTC, H. S. Teoh wrote:
> > On Thu, Jul 28, 2022 at 02:30:38PM +0000, pascal111 via
> > Digitalmars-d-learn wrote: [...]
> > > 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.
> > 
> > Just use the source, Luke!  Phobos is open source for a reason.
> > 
> > 	https://github.com/dlang/phobos/blob/8280b1e7de6cca4dc9a593431591054a5b3aa288/std/math/traits.d#L694
[...]
> I think Phobos is the big library of D, is it the same one with gdc
> compiler too? I'm using gdc compiler.

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

-- 
What's the difference between a 4D tube and an overweight Dutchman?  One is a hollow spherinder, and the other is a spherical Hollander.