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, 12 insertions, 0 deletions

diff --git a/odb/mysql/forward.hxx b/odb/mysql/forward.hxx
index 75aeff0..94b175b 100644
--- a/odb/mysql/forward.hxx
+++ b/odb/mysql/forward.hxx
@@ -8,12 +8,15 @@
 
 #include <odb/pre.hxx>
 
+#include <odb/forward.hxx>
+
 namespace odb
 {
   namespace mysql
   {
     class database;
     class connection;
+    typedef details::shared_ptr<connection> connection_ptr;
     class connection_factory;
     class transaction;
     class query;
@@ -29,6 +32,15 @@ namespace odb
     template <typename T>
     class container_statements;
   }
+
+  namespace details
+  {
+    template <>
+    struct counter_type<mysql::connection>
+    {
+      typedef shared_base counter;
+    };
+  }
 }
 
 #include <odb/post.hxx>