Implement nested id support

Now the 'id' specifier can optionally include the data member path
to the id inside the composite value. For example:

#pragma db id(first)
std::pair<int, int> p;

Note that one somewhat counter-intuitive aspect of this new feature
is that the whole member marked with id ('p' in the above example)
and not just the actual id member ('p.first' in the above example)
is treated as readonly.

Such nested id also cannot be automatically assigned (auto specifier).

1 files changed, 12 insertions, 12 deletions

diff --git a/odb/relational/source.hxx b/odb/relational/source.hxx
index e67931f..f495cef 100644
--- a/odb/relational/source.hxx
+++ b/odb/relational/source.hxx
@@ -211,7 +211,7 @@ namespace relational
           semantics::class_& imc (
             poly ? dynamic_cast<semantics::class_&> (imf.scope ()) : c);
 
-          semantics::data_member& id (*id_member (imc));
+          data_member_path& id (*id_member (imc));
           semantics::type& idt (utype (id));
 
           if (container (imb))
@@ -484,7 +484,7 @@ namespace relational
         instance<object_columns_list> l_cols; // Our id columns.
         instance<object_columns_list> r_cols; // Other side id columns.
 
-        semantics::data_member& id (*id_member (*us.obj));
+        data_member_path& id (*id_member (*us.obj));
 
         l_cols->traverse (id);
 
@@ -1018,7 +1018,7 @@ namespace relational
               dt = quote_id (table);
               da = quote_id (poly ? alias + "_" + table.uname () : alias);
 
-              semantics::data_member& id (*id_member (c));
+              data_member_path& id (*id_member (c));
 
               instance<object_columns_list> oid_cols, cid_cols;
               oid_cols->traverse (id);
@@ -1171,7 +1171,7 @@ namespace relational
       bool query_;
       size_t depth_;
       string table_;
-      semantics::data_member& id_;
+      data_member_path& id_;
       instance<object_columns_list> id_cols_;
     };
 
@@ -1391,7 +1391,7 @@ namespace relational
 
           // Order of these tests is important.
           //
-          if (!insert_send_auto_id && id (mi.m) && auto_ (mi.m))
+          if (!insert_send_auto_id && auto_ (mi.m))
             os << "if (sk != statement_insert && sk != statement_update)"
                << "{";
           else if (section_ == 0 && separate_load (mi.m))
@@ -1567,7 +1567,7 @@ namespace relational
 
           // The same logic as in pre().
           //
-          if (!insert_send_auto_id && id (mi.m) && auto_ (mi.m))
+          if (!insert_send_auto_id && auto_ (mi.m))
             block = true;
           else if (section_ == 0 && separate_load (mi.m))
             block = true;
@@ -1673,7 +1673,7 @@ namespace relational
         size_t insert (cc.total - cc.inverse - cc.optimistic_managed);
         size_t update (insert - cc.id - cc.readonly - cc.separate_update);
 
-        semantics::data_member* id;
+        data_member_path* id;
         if (!insert_send_auto_id && (id = id_member (c)) != 0 && auto_ (*id))
           insert -= cc.id;
 
@@ -2041,7 +2041,7 @@ namespace relational
           // If we don't send auto id in INSERT statement, ignore this
           // member altogether (we never send auto id in UPDATE).
           //
-          if (!insert_send_auto_id && id (mi.m) && auto_ (mi.m))
+          if (!insert_send_auto_id && auto_ (mi.m))
             return false;
 
           os << "// " << mi.m.name () << endl
@@ -2985,7 +2985,7 @@ namespace relational
         bool poly_derived (poly && poly_root != &c);
         size_t poly_depth (poly_derived ? polymorphic_depth (c) : 1);
 
-        semantics::data_member* idm (id_member (poly ? *poly_root : c));
+        data_member_path* idm (id_member (poly ? *poly_root : c));
 
         os << "// " << mi.m.name () << (pre_ ? " pre" : " post") << endl
            << "//" << endl;
@@ -3084,7 +3084,7 @@ namespace relational
               for (size_t i (0); i < poly_depth - 1; ++i)
                 id_im += (i == 0 ? ".base" : "->base");
 
-              string const& n (idm->name ());
+              string const& n (idm->front ()->name ());
               id_var = id_im + (poly_derived ? "->" : ".") + n +
                 (n[n.size () - 1] == '_' ? "" : "_");
 
@@ -3563,7 +3563,7 @@ namespace relational
             if (polymorphic (*c))
               c = &dynamic_cast<semantics::class_&> (imf.scope ());
 
-            semantics::data_member& inv_id (*id_member (*c));
+            data_member_path& inv_id (*id_member (*c));
 
             qname inv_table;                            // Other table name.
             string inv_qtable;
@@ -6456,7 +6456,7 @@ namespace relational
 
         if (version (m))
           p = version_value (m);
-        else if (context::id (m) && auto_ (m)) // Only simple id can be auto.
+        else if (auto_ (m)) // Only simple, direct id can be auto.
           p = qp_.auto_id ();
         else
           p = qp_.next ();