leaving aside the question of whether its a good idea, here's how to get it to
compile:
with devel and new-style concepts:
type
Concept0* = concept
proc copy_C0(x:Self):Self
proc init_C0(x:var Self)
Concept1* = concept
proc copy_C1(s:Self,x:Concept0):Self
proc init_C1(s:var Self,x:Concept0)
Concept2* = concept
proc copy_C2(s:Self,x:Concept1):Self
proc init_C2(s:var Self,x:Concept1)
Run
with old-style concepts:
type
Concept0* = concept c,var v,type t
copy_C0(c) is t
init_C0(v)
Concept1*[T:Concept0] = concept c, var v, type t
copy_C1(c,T) is t
init_C1(v,T)
Concept2*[T:Concept1] = concept c,var v, type t
copy_C2(c,T) is t
init_C2(v,T)
Run
