Variadic argument lists https://dlang.org/spec/function.html#variadic
fixed number of arguments
(T t, ...) can be C-style (core.stdc.stdarg) or D-style (core.vararg)
(T t ...) typesafe https://dlang.org/spec/function.html#typesafe_variadic_functions
or https://dlang.org/spec/function.html#typesafe_variadic_functions
See Implementation
Variadic argument lists https://dlang.org/spec/function.html#variadic