Dual behavior

[doofenstein]

usually one would name the inplace variant with a verb in infinitive (e.g. sort 
or draw) and the copying variant with the past participle (e.g. sorted or 
drawn). Though to minimise duplicated code there's the [dup macro in 
sugar](https://nim-lang.org/docs/sugar.html#dup.m%2CT%2Cvarargs%5Buntyped%5D).