[Issue 13371] std.math.factorial

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13371

safety0ff.bugz <safety0ff.bugz at gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |safety0ff.bugz at gmail.com

--- Comment #5 from safety0ff.bugz <safety0ff.bugz at gmail.com> ---
(In reply to bearophile_hugs from comment #4)
> (In reply to Don from comment #2)
> 
> > And for BigInt, iterated multiplication isn't a good way of caclulating
> > factorials.
> 
> Right, for BigInt you can add a different specialization later for bigints.
> 

Generic functions for computing BigInt results often end up hitting one
limitation or another.

I think that any BigInt functions worth providing in phobos should be
implemented within BigInt.

With factorial for example, there will be garbage creation for intermediate
results that could be eliminated if implemented in BigInt.

--