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Diffstat (limited to 'checker/univ.ml')
| -rw-r--r-- | checker/univ.ml | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/checker/univ.ml b/checker/univ.ml index 46b3ce680..ebc37bc10 100644 --- a/checker/univ.ml +++ b/checker/univ.ml @@ -1011,6 +1011,13 @@ struct A'] as opposed to [A' <= A]. *) type t = Irrelevant | Covariant | Invariant + let check_subtype x y = match x, y with + | (Irrelevant | Covariant | Invariant), Irrelevant -> true + | Irrelevant, Covariant -> false + | (Covariant | Invariant), Covariant -> true + | (Irrelevant | Covariant), Invariant -> false + | Invariant, Invariant -> true + let leq_constraint csts variance u u' = match variance with | Irrelevant -> csts |