Namespace management for static multi-database support

Now in libodb the odb::core namespace is split into odb::common (database-
independent stuff) and odb::core proper, which imports odb::common. Each
database runtime now defines odb::<db>::core namespace which also imports
odb::common and adds the database-specific bits. The overall idea is that
one can do using namespace odb::<db>::core just like for odb::core.

9 files changed, 36 insertions, 14 deletions

diff --git a/odb/callback.hxx b/odb/callback.hxx
index 20326e4..6a836e3 100644
--- a/odb/callback.hxx
+++ b/odb/callback.hxx
@@ -7,6 +7,7 @@
 
 #include <odb/pre.hxx>
 
+#include <odb/forward.hxx>        // odb::core
 #include <odb/details/export.hxx>
 
 namespace odb
@@ -32,7 +33,7 @@ namespace odb
     value v_;
   };
 
-  namespace core
+  namespace common
   {
     using odb::callback_event;
   }
diff --git a/odb/exception.hxx b/odb/exception.hxx
index 004ed65..823d785 100644
--- a/odb/exception.hxx
+++ b/odb/exception.hxx
@@ -9,6 +9,7 @@
 
 #include <exception>
 
+#include <odb/forward.hxx>        // odb::core
 #include <odb/details/export.hxx>
 
 namespace odb
@@ -19,7 +20,7 @@ namespace odb
     what () const throw () = 0;
   };
 
-  namespace core
+  namespace common
   {
     using odb::exception;
   }
diff --git a/odb/exceptions.hxx b/odb/exceptions.hxx
index 90729fc..df14928 100644
--- a/odb/exceptions.hxx
+++ b/odb/exceptions.hxx
@@ -9,6 +9,7 @@
 
 #include <string>
 
+#include <odb/forward.hxx>    // odb::core
 #include <odb/exception.hxx>
 
 #include <odb/details/export.hxx>
@@ -188,7 +189,7 @@ namespace odb
     std::string what_;
   };
 
-  namespace core
+  namespace common
   {
     using odb::null_pointer;
 
diff --git a/odb/forward.hxx b/odb/forward.hxx
index 705acd3..fe23c5f 100644
--- a/odb/forward.hxx
+++ b/odb/forward.hxx
@@ -14,6 +14,19 @@
 
 namespace odb
 {
+  // Common and core namespaces. The idea is that you can use the
+  // using directive to get database-independent (common) names or
+  // all core names (core).
+  //
+  namespace common {}
+
+  namespace core
+  {
+    using namespace common;
+  }
+
+  //
+  //
   class database;
   class connection;
   typedef details::shared_ptr<connection> connection_ptr;
@@ -21,6 +34,11 @@ namespace odb
   class statement;
   class session;
 
+  namespace common
+  {
+    using odb::session;
+  }
+
   namespace core
   {
     using odb::database;
@@ -28,7 +46,6 @@ namespace odb
     using odb::connection_ptr;
     using odb::transaction;
     using odb::statement;
-    using odb::session;
   }
 
   // Tracing.
@@ -36,7 +53,7 @@ namespace odb
   class tracer; // Not in core.
   extern LIBODB_EXPORT tracer& stderr_tracer;
 
-  namespace core
+  namespace common
   {
     using odb::stderr_tracer;
   }
diff --git a/odb/lazy-ptr.hxx b/odb/lazy-ptr.hxx
index 8df47b9..3de8dab 100644
--- a/odb/lazy-ptr.hxx
+++ b/odb/lazy-ptr.hxx
@@ -10,7 +10,7 @@
 #include <memory>  // std::auto_ptr, std::shared_ptr/weak_ptr
 #include <utility> // std::move
 
-#include <odb/forward.hxx>        // odb::database
+#include <odb/forward.hxx>        // odb::core, odb::database
 #include <odb/traits.hxx>
 #include <odb/lazy-ptr-impl.hxx>
 #include <odb/details/config.hxx> // ODB_CXX11
@@ -627,7 +627,7 @@ namespace odb
 
 #endif // ODB_CXX11
 
-  namespace core
+  namespace common
   {
     using odb::lazy_ptr;
     using odb::lazy_auto_ptr;
diff --git a/odb/nullable.hxx b/odb/nullable.hxx
index e3c9bc8..565b4ee 100644
--- a/odb/nullable.hxx
+++ b/odb/nullable.hxx
@@ -7,6 +7,8 @@
 
 #include <odb/pre.hxx>
 
+#include <odb/forward.hxx> // odb::core
+
 namespace odb
 {
   template <typename T>
@@ -52,7 +54,7 @@ namespace odb
     bool null_;
   };
 
-  namespace core
+  namespace common
   {
     using odb::nullable;
   }
diff --git a/odb/prepared-query.hxx b/odb/prepared-query.hxx
index 53d8110..928f078 100644
--- a/odb/prepared-query.hxx
+++ b/odb/prepared-query.hxx
@@ -7,7 +7,7 @@
 
 #include <odb/pre.hxx>
 
-#include <odb/forward.hxx>
+#include <odb/forward.hxx> // odb::core
 #include <odb/traits.hxx>
 #include <odb/result.hxx>
 #include <odb/statement.hxx>
@@ -162,7 +162,7 @@ namespace odb
     prepared_query_impl* impl_;
   };
 
-  namespace core
+  namespace common
   {
     using odb::prepared_query;
   }
diff --git a/odb/result.hxx b/odb/result.hxx
index 5db08cd..d90ceb0 100644
--- a/odb/result.hxx
+++ b/odb/result.hxx
@@ -9,7 +9,7 @@
 
 #include <cstddef>  // std::ptrdiff_t, std::size_t
 
-#include <odb/forward.hxx>
+#include <odb/forward.hxx> // odb::core
 #include <odb/traits.hxx>
 
 #include <odb/details/export.hxx>
@@ -215,7 +215,7 @@ namespace odb
     details::shared_ptr<result_impl_type> impl_;
   };
 
-  namespace core
+  namespace common
   {
     using odb::result;
     using odb::result_iterator;
diff --git a/odb/schema-catalog.hxx b/odb/schema-catalog.hxx
index d79d0b3..861c3d0 100644
--- a/odb/schema-catalog.hxx
+++ b/odb/schema-catalog.hxx
@@ -9,7 +9,7 @@
 
 #include <string>
 
-#include <odb/forward.hxx>
+#include <odb/forward.hxx> // odb::core
 
 #include <odb/details/export.hxx>
 
@@ -22,7 +22,7 @@ namespace odb
     create_schema (database&, const std::string& name = "");
   };
 
-  namespace core
+  namespace common
   {
     using odb::schema_catalog;
   }