On Friday, November 25, 2016 17:03:32 Artur Skawina via Digitalmars-d-learn wrote: > On 11/25/16 15:51, Jonathan M Davis via Digitalmars-d-learn wrote: > > On Friday, November 25, 2016 14:27:39 Igor Shirkalin via > > Digitalmars-d-learn> > > wrote: > >> I think you may write it (I mean actual D) with using some > >> template like this: > >> > >> auto array = static_array!uint(1, 2, 3, 4) > >> > >> Could you please help to write down this template in the best and > >> clear manner? > > > > That's easy. The problem is if you want it to have the same semantics as > > > > uint[4] arr = [1, 2, 3, 4]; > > > > In particular, VRP (Value Range Propagation) is a problem. This compiles > > > > ubyte[4] arr = [1, 2, 3, 4]; > > > > because each of the arguments is known to fit in a ubyte. However, > > making > > > > auto arr = staticArray!ubyte(1, 2, 3, 4); > > > > do the same without forcing a cast is difficult. [...] > > enum T[N] staticArray(T, alias ELS, size_t N=ELS.length) = ELS; > auto arr = staticArray!(ubyte, [1, 2, 3, 4]);
That won't work with variables. e.g. ubyte a; auto arr = staticArray!(ubyte, [1, 2, 3, 4, a]); would fail to compile. It only works when all of the values are known at compile time, whereas ubyte a; ubyte[5] arr = [1, 2, 3, 4, a]; would compile just fine. - Jonathan M Davis
