standard-classes.md

@@ -138,6 +138,8 @@ Issues:
 
 - `succ` and `pred` are unused.
 - The default definitions of `enum`\* would make more sense if `toEnum` and `fromEnum` used `Integer` instead of `Int`.
+- Some doubt that it makes sense to have `Float` and `Double` instances.
+- It is wierd that `[0,3..20]::[Rational]` includes `21`.
 
 ### The Ix class
 
@@ -154,3 +156,22 @@ Proposal:
 
 - Make `Show` a superclass of `Ix`, so that the offending index and range can be shown in exceptions.
   (All instances of `Ix` in the `base` package are also instances of `Show`.)
+
+### The Bits class
+
+
+
+Issues:
+
+
+- The `Num` superclass may unduly restrict instances.  The only thing actually needed from `Num` is 0.
+- The `bitSize` method is not defined for all instances, and there is no general way to test whether it can be safely called.
+
+### The Storable class
+
+
+
+Issues:
+
+
+- Some interfaces require clients to manage the memory for objects, but to treat them abstractly.  In such cases one wants to define `sizeOf` and `alignment` (to use `malloc` or `alloca`), but not `peek` or `poke`.