def checked_pick

bend-collections-laws-crypto@1.0.0.0 · spec/math/generic.bend:63

import Base
import bend-collections-laws-crypto@1.0.0.0/src/math/num.bend as N

63def checked_pick(~T: Data, ~of: Nat -> T, +n: Nat, ok: Bool) -> Result<&2, &2, N.NumError, T>:
64  match ok:
65    case True{}:
66      Done{of(n)}
67    case False{}:
68      Fail{N.Overflow{}}