returning constant references from class methods

[Kagamin via Digitalmars-d-learn]

On Tuesday, 19 July 2016 at 12:30:49 UTC, celavek wrote:
>     final ulong[char] nucleotide_counts () const
>     {
>         return cached_counts;
>     }

BTW you can find enumap useful 
https://forum.dlang.org/post/hloitwqnisvtgfougncf@forum.dlang.org 
if you want to have small associative arrays with enum keys.