EntryID implementation changes for #956

- move the santitise operation up into EntryID's ctor
- turn the recast() operation into a real in-place cast

these changes should be transparent to the existing usages
of EntryID (within the asset framework), but allow for use
as attribute name holder in GenNode, since we're now able
to feed existing name/ID values directly into the ctor
of BareEntryID, without any spurious santitise operation.

src/lib/idi/entry-id.hpp

@@ -133,7 +133,7 @@ namespace idi {
        * generates differing hash-IDs for different type parameters
        */
       BareEntryID (string const& symbolID, HashVal seed =0)
-        : symbol_(util::sanitise(symbolID))
+        : symbol_(symbolID)
         , hash_(buildHash (symbol_, seed))
         { }
       
@@ -169,7 +169,7 @@ namespace idi {
       
       
       template<typename TAR>
-      EntryID<TAR> recast()  const;
+      EntryID<TAR> const& recast()  const;
       
     };
   
@@ -211,7 +211,7 @@ namespace idi {
        */
       explicit
       EntryID (string const& symbolID)
-        : BareEntryID (symbolID, getTypeHash<TY>())
+        : BareEntryID (util::sanitise(symbolID), getTypeHash<TY>())
         { }
       
       
@@ -226,14 +226,14 @@ namespace idi {
           return bID.getHash() == buildHash (bID.getSym(), getTypeHash<TY>());
         }
       
-      static EntryID
+      static EntryID const&
       recast (BareEntryID const& bID)
         {
           if (!canRecast(bID))
             throw error::Logic ("unable to recast EntryID: desired type "
                                 "doesn't match original definition"
                                , error::LUMIERA_ERROR_WRONG_TYPE);
-          return EntryID (bID.getSym());
+          return static_cast<EntryID const&> (bID);
         }
       
       
@@ -268,7 +268,8 @@ namespace idi {
    *          Exception if it doesn't match the stored hash.
    */
   template<typename TAR>
-  EntryID<TAR> BareEntryID::recast()  const
+  EntryID<TAR> const&
+  BareEntryID::recast()  const
   {
     return EntryID<TAR>::recast(*this);
   }