Add support for custom database type mapping

New pragma qualifier, map, and specifiers: as, to, from. New tests:
<database>/custom.

1 files changed, 90 insertions, 0 deletions

diff --git a/mssql/custom/traits.hxx b/mssql/custom/traits.hxx
new file mode 100644
index 0000000..34081ed
--- /dev/null
+++ b/mssql/custom/traits.hxx
@@ -0,0 +1,90 @@
+// file      : mssql/types/traits.hxx
+// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#ifndef TRAITS_HXX
+#define TRAITS_HXX
+
+#include <limits>  // std::numeric_limits
+#include <sstream>
+#include <cstring> // std::memcpy
+#include <cassert>
+
+#include <odb/mssql/traits.hxx>
+
+#include "test.hxx" // point
+
+namespace odb
+{
+  namespace mssql
+  {
+#if !defined(MSSQL_SERVER_VERSION) || MSSQL_SERVER_VERSION >= 1000
+    template <>
+    class value_traits<point, id_string>
+    {
+    public:
+      typedef point value_type;
+      typedef point query_type;
+
+      typedef char* image_type;
+
+      static void
+      set_value (point& v,
+                 const char* b,
+                 std::size_t n,
+                 bool is_null)
+      {
+        if (is_null)
+          v = point ();
+        else
+        {
+          // Point format is "POINT (x y)".
+          //
+          std::istringstream is (std::string (b + 7, n - 7));
+
+          is >> v.x;
+          is >> v.y;
+        }
+      }
+
+      static void
+      set_image (char* b,
+                 std::size_t c,
+                 std::size_t& n,
+                 bool& is_null,
+                 const point& v)
+      {
+        is_null = false;
+        std::ostringstream os;
+
+        // The formula for the number of decimla digits required is given in:
+        //
+        // http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1822.pdf
+        //
+        os.precision (std::numeric_limits<double>::digits10);
+        // os.precision (2 + std::numeric_limits<double>::digits * 301/1000);
+
+        os << "POINT (" << v.x << ' ' << v.y << ')';
+
+        const std::string& s (os.str ());
+        n = s.size ();
+        assert (n <= c);
+        std::memcpy (b, s.c_str (), n);
+      }
+    };
+
+    template <>
+    struct type_traits<point>
+    {
+      static const database_type_id db_type_id = id_string;
+
+      struct conversion
+      {
+        static const char* to () {return "GEOMETRY::STGeomFromText((?), 0)";}
+      };
+    };
+#endif // SQL Server > 2005
+  }
+}
+
+#endif // TRAITS_HXX