Add odb::connection class

This abstract class represents a connection to the database. One can
use it to start a transaction or to execute a native statement out
of a transaction.

Before we had concrete connection classes in the database runtime
libraries (e.g., odb::mysql::connection). Now these classes derive
from odb::connection.

1 files changed, 35 insertions, 0 deletions

diff --git a/odb/tracer/forward.hxx b/odb/tracer/forward.hxx
new file mode 100644
index 0000000..61f0eb7
--- /dev/null
+++ b/odb/tracer/forward.hxx
@@ -0,0 +1,35 @@
+// file      : odb/tracer/forward.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2005-2011 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#ifndef ODB_TRACER_FORWARD_HXX
+#define ODB_TRACER_FORWARD_HXX
+
+#include <odb/pre.hxx>
+
+#include <odb/forward.hxx>
+
+namespace odb
+{
+  namespace tracer
+  {
+    class database;
+    class connection;
+    typedef details::shared_ptr<connection> connection_ptr;
+    class transaction;
+  }
+
+  namespace details
+  {
+    template <>
+    struct counter_type<tracer::connection>
+    {
+      typedef shared_base counter;
+    };
+  }
+}
+
+#include <odb/post.hxx>
+
+#endif // ODB_TRACER_FORWARD_HXX