Existing Class now works with universe polymorphism. Fixes HoTT bug #063

2 files changed, 18 insertions, 9 deletions

diff --git a/pretyping/typeclasses.ml b/pretyping/typeclasses.ml
index 8364387783..dd09d5b29a 100644
--- a/pretyping/typeclasses.ml
+++ b/pretyping/typeclasses.ml
@@ -403,9 +403,9 @@ let add_class cl =
 
 
 open Declarations
-(* FIXME: deal with universe instances *)
+
 let add_constant_class cst =
-  let ty = Typeops.type_of_constant_in (Global.env ()) (cst,Univ.Instance.empty) in
+  let ty = Universes.unsafe_type_of_global (ConstRef cst) in
   let ctx, arity = decompose_prod_assum ty in
   let tc = 
     { cl_impl = ConstRef cst;
@@ -420,9 +420,10 @@ let add_inductive_class ind =
   let mind, oneind = Global.lookup_inductive ind in
   let k =
     let ctx = oneind.mind_arity_ctxt in
+    let inst = Univ.UContext.instance mind.mind_universes in
     let ty = Inductive.type_of_inductive_knowing_parameters
       (push_rel_context ctx (Global.env ()))
-      ((mind,oneind),Univ.Instance.empty)
+      ((mind,oneind),inst)
       (Array.map (fun x -> lazy x) (Termops.extended_rel_vect 0 ctx))
     in
       { cl_impl = IndRef ind;
diff --git a/test-suite/bugs/opened/HoTT_coq_063.v b/test-suite/bugs/closed/HoTT_coq_063.v
index 8656fadaa9..777f6483d5 100644
--- a/test-suite/bugs/opened/HoTT_coq_063.v
+++ b/test-suite/bugs/closed/HoTT_coq_063.v
@@ -8,9 +8,13 @@ Module A.
   | BuildContr : forall A (center : A) (contr : forall y, center = y), IsTrunc 0 A
   | trunc_S : forall A n, (forall x y : A, IsTrunc n (x = y)) -> IsTrunc (S n) A.
 
-  Fail Existing Class IsTrunc.
-  (* Anomaly: Mismatched instance and context when building universe substitution.
-Please report. *)
+  Existing Class IsTrunc.
+
+
+  Instance is_trunc_unit : IsTrunc 0 unit.
+  Proof. apply BuildContr with (center:=tt). now intros []. Defined.
+
+  Check (_ : IsTrunc 0 unit).
 End A.
 
 Module B.
@@ -20,7 +24,11 @@ Module B.
       | S _ => False
     end.
 
-  Fail Existing Class IsTrunc.
-  (* Anomaly: Mismatched instance and context when building universe substitution.
-Please report. *)
+  Existing Class IsTrunc.
+
+  Instance is_trunc_unit : IsTrunc 0 unit.
+  Proof. exact I. Defined.
+
+  Check (_ : IsTrunc 0 unit).
+  Fail Definition foo := (_ : IsTrunc 1 unit).
 End B.