On Thu, Jan 22, 2015 at 05:12:17PM +0000, Russel Winder via Digitalmars-d-learn wrote: > Using reduce for factorial, seems to require iota, not a bad things > per se, with ulongs: > > reduce!"a*b"(1, iota(1, n + 1)) > > works fine. Now switch to BigInt: > > reduce!"a*b"(one, iota(one, n + one)) > > fails to compile, one and n + one are of different types. Problem is > that one is immutable but n + one is not. I can't remember how to > create an immutable value as an expression so: > > immutable BigInt v = n + one; > reduce!"a*b"(one, iota(one, v)) > > now I get an error telling me that I can't use iota because BigInt is > not a float or an integer. Is this a known bug? Yes it is: > https://issues.dlang.org/show_bug.cgi?id=6447 > > Does anyone know how to fix this 3.5 year old bug that is a blocker > for doing anything with factorial and Fibonacci Series.? [...]
https://github.com/D-Programming-Language/phobos/pull/2895 This is just the tip of the iceberg. The full enhancement is described in: https://issues.dlang.org/show_bug.cgi?id=10762 T -- Give a man a fish, and he eats once. Teach a man to fish, and he will sit forever.
