#define ATS_DYNLOADFLAG 0
staload "lib/SATS/valid.sats"

assume valid(a:viewt@ype,b:bool) = (a,bool b) 

implement{a} create_valid(value) = (value,true)

// Create unvalid value by casting null pointer to type.
implement{a} create_unvalid() = let
  staload UN = "prelude/SATS/unsafe.sats"
in
  ($extval(a,"(void *)NULL"),false) //UNSAFE:
end

implement{a} unwrap_valid(v) = v.0

implement{a} is_valid(v) = v.1