foreign-data.md

@@ -54,3 +54,21 @@ It is anoying that \<n\> must be a constant and \<type\> must be a builtin, but
 
 
 A possible extension would be to allow implementations to derive instances of Storable and allow types with such derived instances be used in foreign space declarations too.
+
+
+another possibility is the definition of 'manifestly constant' data. which is defined as declarations of the form
+
+```wiki
+name :: built-in-type
+name = <constant>
+
+or sizeof a builtin
+
+or 'foo <op> bar' where foo and bar are manifestly constant and op is a basic operation.
+```
+
+
+then allow such manifestly constant values for n and allow types whose sizeof is manifestly constant to be used in foreign space declarations.
+
+
+however, this is probably a lot of work for a problem that has better workarounds unless other uses for manifestly constant data are found.