fixes #4672

compiler/sigmatch.nim

@@ -1075,7 +1075,7 @@ proc typeRel(c: var TCandidate, f, aOrig: PType, doBind = true): TTypeRelation =
   of tyBuiltInTypeClass:
     considerPreviousT:
       let targetKind = f.sons[0].kind
-      if targetKind == a.skipTypes({tyRange, tyGenericInst}).kind or
+      if targetKind == a.skipTypes({tyRange, tyGenericInst, tyBuiltInTypeClass}).kind or
          (targetKind in {tyProc, tyPointer} and a.kind == tyNil):
         put(c, f, a)
         return isGeneric

tests/generics/ttypeclass_to_typeclass.nim

@@ -0,0 +1,12 @@
+# bug #4672
+type
+  EnumContainer[T: enum] = object
+    v: T
+  SomeEnum {.pure.} = enum
+    A,B,C
+
+proc value[T: enum](this: EnumContainer[T]): T =
+  this.v
+
+var enumContainer: EnumContainer[SomeEnum]
+discard enumContainer.value()