Modern C++ Lamentations

[Timon Gehr]

On 29.12.18 10:29, Walter Bright wrote:
> http://aras-p.info/blog/2018/12/28/Modern-C-Lamentations/
> 
> Time to show off your leet D skilz and see how good we can do it in D!


Current D:
---
import std.range, std.algorithm, std.typecons;
import std.bigint, std.stdio;
alias then(alias a)=(r)=>map!a(r).joiner;
void main(){
     auto triples=recurrence!"a[n-1]+1"(1.BigInt)
         .then!(z=>iota(1,z+1).then!(x=>iota(x,z+1).map!(y=>tuple(x,y,z))))
         .filter!((t)=>t[0]^^2+t[1]^^2==t[2]^^2);
     triples.each!((x,y,z){ writeln(x," ",y," ",z); });
}
---

tuple-syntax branch at https://github.com/tgehr/dmd/tree/tuple-syntax
---
import std.range, std.algorithm, std.typecons;
import std.bigint, std.stdio;
alias then(alias a)=(r)=>map!a(r).joiner;
void main(){
     auto triples=recurrence!"a[n-1]+1"(1.BigInt)
         .then!(z=>iota(1,z+1).then!(x=>iota(x,z+1).map!(y=>(x,y,z))))
         .filter!((x,y,z)=>x^^2+y^^2==z^^2);
     triples.each!((x,y,z){ writeln(x," ",y," ",z); });
}
---