# REQUIRE: `not is_error`
fun value: V do return maybe_value.as(V)
- # The require
+ # The error
# REQUIRE: `is_error`
fun error: E do return maybe_error.as(E)
redef fun to_s do
var e = maybe_error
if e != null then return e.to_s
- return value.to_s
+ return value.as(not null).to_s
end
end