Add support for boost::optional and boost::shared_ptr as value wrappers

New test: boost/common/optional.

3 files changed, 57 insertions, 13 deletions

diff --git a/boost/README b/boost/README
index 021d601..5a95ac8 100644
--- a/boost/README
+++ b/boost/README
@@ -9,9 +9,11 @@ employee.hxx
   We use shared_ptr/weak_ptr smart pointers provided by Boost (as well
   as their lazy versions provided by the Boost profile library) to
   establish a bidirectional employee-employer relationship. We also use
-  the boost::gregorian::date type to store the employee's date of birth.
-  Finally, we use the boost::unordered_set container to keep track of
-  the employee's email addresses.
+  the boost::gregorian::date type to store the employee's date of birth
+  and the boost::unordered_set container to keep track of the employee's
+  email addresses Finally, we use boost::optional for the optional middle
+  name. If the middle name is not present, it will be represented in the
+  database as a NULL value.
 
 employee-odb.hxx
 employee-odb.ixx
@@ -45,8 +47,8 @@ driver.cxx
   instance. It then creates a number of 'employee' and 'employer' objects and
   persists them in the database. The next transaction loads all the employees
   of a particular employer using the employee-employer relationship. Finally,
-  the driver performs a database query which uses a data member of the Boost
-  gregorian::date type in its criterion.
+  the driver performs a few database queries which use data members of the
+  various Boost value types in their criterion.
 
 To run the example we may first need to create the database schema (for some
 database systems, such as SQLite, the schema is embedded into the generated
diff --git a/boost/driver.cxx b/boost/driver.cxx
index 2ccaf87..bb1f134 100644
--- a/boost/driver.cxx
+++ b/boost/driver.cxx
@@ -39,7 +39,7 @@ main (int argc, char* argv[])
           new employee ("John", "Doe", date (1975, Jan, 1), er));
 
         shared_ptr<employee> jane (
-          new employee ("Jane", "Doe", date (1976, Feb, 2), er));
+          new employee ("Jane", "Q", "Doe", date (1976, Feb, 2), er));
 
         john->emails ().insert ("john_d@example.com");
         john->emails ().insert ("john.doe@example.com");
@@ -67,7 +67,7 @@ main (int argc, char* argv[])
         shared_ptr<employer> er (new employer ("Complex Systems Inc"));
 
         shared_ptr<employee> john (
-          new employee ("John", "Smith", date (1977, Mar, 3), er));
+          new employee ("John", "Z", "Smith", date (1977, Mar, 3), er));
 
         shared_ptr<employee> jane (
           new employee ("Jane", "Smith", date (1978, Apr, 4), er));
@@ -109,8 +109,14 @@ main (int argc, char* argv[])
         lazy_weak_ptr<employee>& lwp (*i);
         shared_ptr<employee> p (lwp.load ()); // Load and lock.
 
-        cout << p->first () << " " << p->last () << endl
-             << "  born: " << p->born () << endl
+        cout << p->first () << " ";
+
+        if (p->middle ())
+          cout << *p->middle () << " ";
+
+        cout << p->last () << endl;
+
+        cout << "  born: " << p->born () << endl
              << "  employer: " << p->employer ()->name () << endl;
 
         for (emails::const_iterator j (p->emails ().begin ());
@@ -125,13 +131,13 @@ main (int argc, char* argv[])
       t.commit ();
     }
 
+    typedef odb::query<employee> query;
+    typedef odb::result<employee> result;
+
     // Search for Complex Systems Inc employees that were born before
     // April 1978.
     //
     {
-      typedef odb::query<employee> query;
-      typedef odb::result<employee> result;
-
       session s;
       transaction t (db->begin ());
 
@@ -142,6 +148,21 @@ main (int argc, char* argv[])
       for (result::iterator i (r.begin ()); i != r.end (); ++i)
         cout << i->first () << " " << i->last () << " " << i->born () << endl;
 
+      cout << endl;
+      t.commit ();
+    }
+
+    // Search for all the employees that don't have a middle name.
+    //
+    {
+      session s;
+      transaction t (db->begin ());
+
+      result r (db->query<employee> (query::middle.is_null ()));
+
+      for (result::iterator i (r.begin ()); i != r.end (); ++i)
+        cout << i->first () << " " << i->last () << endl;
+
       t.commit ();
     }
   }
diff --git a/boost/employee.hxx b/boost/employee.hxx
index ffa017e..952f065 100644
--- a/boost/employee.hxx
+++ b/boost/employee.hxx
@@ -10,6 +10,7 @@
 
 #include <boost/shared_ptr.hpp>
 #include <boost/weak_ptr.hpp>
+#include <boost/optional.hpp>
 #include <boost/unordered_set.hpp>
 #include <boost/date_time/gregorian/gregorian.hpp>
 
@@ -86,7 +87,20 @@ public:
             const std::string& last,
             const date& born,
             shared_ptr<employer_type> employer)
-      : first_ (first), last_ (last), born_ (born), employer_ (employer)
+      : first_ (first), last_ (last),
+        born_ (born),
+        employer_ (employer)
+  {
+  }
+
+  employee (const std::string& first,
+            const std::string& middle,
+            const std::string& last,
+            const date& born,
+            shared_ptr<employer_type> employer)
+      : first_ (first), middle_ (middle), last_ (last),
+        born_ (born),
+        employer_ (employer)
   {
   }
 
@@ -98,6 +112,12 @@ public:
     return first_;
   }
 
+  const boost::optional<std::string>&
+  middle () const
+  {
+    return middle_;
+  }
+
   const std::string&
   last () const
   {
@@ -151,6 +171,7 @@ private:
   unsigned long id_;
 
   std::string first_;
+  boost::optional<std::string> middle_;
   std::string last_;
 
   date born_;