Add support for value wrappers

Wrapper is a class that wraps another type. Examples of wrappers are
various smart pointers, holders, etc. A wrapper can be transparent or
it can handle the NULL semantics.

The new odb::nullable class template is a NULL wrapper that helps
to add the NULL semantics to a value type.

New test: common/wrapper.

6 files changed, 237 insertions, 2 deletions

diff --git a/common/makefile b/common/makefile
index a27d212..522cc4c 100644
--- a/common/makefile
+++ b/common/makefile
@@ -21,7 +21,8 @@ lifecycle     \
 query         \
 relationship  \
 schema        \
-template
+template      \
+wrapper
 
 thread_tests := threads
 
diff --git a/common/wrapper/driver.cxx b/common/wrapper/driver.cxx
new file mode 100644
index 0000000..ed4d83f
--- /dev/null
+++ b/common/wrapper/driver.cxx
@@ -0,0 +1,73 @@
+// file      : common/wrapper/driver.cxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+// Test wrapper machinery.
+//
+
+#include <memory>   // std::auto_ptr
+#include <cassert>
+#include <iostream>
+
+#include <odb/database.hxx>
+#include <odb/transaction.hxx>
+
+#include <common/common.hxx>
+
+#include "test.hxx"
+#include "test-odb.hxx"
+
+using namespace std;
+using namespace odb::core;
+
+int
+main (int argc, char* argv[])
+{
+  try
+  {
+    auto_ptr<database> db (create_database (argc, argv));
+
+    //
+    //
+    unsigned long id;
+    {
+      object o;
+      o.num.reset (new unsigned long (123));
+      o.nstrs.push_back (nullable_string ());
+      o.nstrs.push_back (nullable_string ("123"));
+#ifdef HAVE_TR1_MEMORY
+      o.tr1_strs.push_back (tr1_nullable_string ());
+      o.tr1_strs.push_back (tr1_nullable_string (new string ("123")));
+#endif
+
+      transaction t (db->begin ());
+      id = db->persist (o);
+      t.commit ();
+    }
+
+    //
+    //
+    {
+      transaction t (db->begin ());
+      auto_ptr<object> o (db->load<object> (id));
+      t.commit ();
+
+      assert (*o->num == 123);
+      assert (o->str.get () == 0);
+      assert (o->nstr.null ());
+      assert (o->nstrs[0].null ());
+      assert (o->nstrs[1].get () == "123");
+#ifdef HAVE_TR1_MEMORY
+      assert (!o->tr1_str);
+      assert (!o->tr1_strs[0]);
+      assert (*o->tr1_strs[1] == "123");
+#endif
+    }
+  }
+  catch (const odb::exception& e)
+  {
+    cerr << e.what () << endl;
+    return 1;
+  }
+}
diff --git a/common/wrapper/makefile b/common/wrapper/makefile
new file mode 100644
index 0000000..3a9b98d
--- /dev/null
+++ b/common/wrapper/makefile
@@ -0,0 +1,108 @@
+# file      : common/wrapper/makefile
+# author    : Boris Kolpackov <boris@codesynthesis.com>
+# copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC
+# license   : GNU GPL v2; see accompanying LICENSE file
+
+include $(dir $(lastword $(MAKEFILE_LIST)))../../build/bootstrap.make
+
+cxx_tun := driver.cxx
+odb_hdr := test.hxx
+cxx_obj := $(addprefix $(out_base)/,$(cxx_tun:.cxx=.o) $(odb_hdr:.hxx=-odb.o))
+cxx_od  := $(cxx_obj:.o=.o.d)
+
+common.l             := $(out_root)/libcommon/common/common.l
+common.l.cpp-options := $(out_root)/libcommon/common/common.l.cpp-options
+
+driver  := $(out_base)/driver
+dist    := $(out_base)/.dist
+test    := $(out_base)/.test
+clean   := $(out_base)/.clean
+
+# Import.
+#
+$(call import,\
+  $(scf_root)/import/odb/stub.make,\
+  odb: odb,odb-rules: odb_rules)
+
+# Build.
+#
+$(driver): $(cxx_obj) $(common.l)
+$(cxx_obj) $(cxx_od): cpp_options := -I$(out_base) -I$(src_base)
+$(cxx_obj) $(cxx_od): $(common.l.cpp-options)
+
+genf := $(addprefix $(odb_hdr:.hxx=-odb),.hxx .ixx .cxx) $(odb_hdr:.hxx=.sql)
+gen  := $(addprefix $(out_base)/,$(genf))
+
+$(gen): $(odb)
+$(gen): odb := $(odb)
+$(gen) $(dist): export odb_options += --database $(db_id) --generate-schema
+$(gen): cpp_options := -I$(src_base)
+$(gen): $(common.l.cpp-options)
+
+$(call include-dep,$(cxx_od),$(cxx_obj),$(gen))
+
+# Alias for default target.
+#
+$(out_base)/: $(driver)
+
+# Dist
+#
+name := $(subst /,-,$(subst $(src_root)/common/,,$(src_base)))
+
+$(dist): db_id := @database@
+$(dist): sources := $(cxx_tun)
+$(dist): headers := $(odb_hdr)
+$(dist): data_dist := test.std
+$(dist): export name := $(name)
+$(dist): export extra_dist := $(data_dist) $(call vc9projs,$(name)) \
+$(call vc10projs,$(name))
+$(dist):
+	$(call dist-data,$(sources) $(headers) $(data_dist))
+	$(call meta-automake,../template/Makefile.am)
+	$(call meta-vc9projs,../template/template,$(name))
+	$(call meta-vc10projs,../template/template,$(name))
+
+# Test.
+#
+$(test): $(driver) $(src_base)/test.std
+	$(call schema)
+	$(call message,test $<,$< --options-file $(dcf_root)/db.options \
+>$(out_base)/test.out)
+	$(call message,,diff -u $(src_base)/test.std $(out_base)/test.out)
+	$(call message,,rm -f $(out_base)/test.out)
+
+# Clean.
+#
+$(clean):                            \
+  $(driver).o.clean                  \
+  $(addsuffix .cxx.clean,$(cxx_obj)) \
+  $(addsuffix .cxx.clean,$(cxx_od))  \
+  $(addprefix $(out_base)/,$(odb_hdr:.hxx=-odb.cxx.hxx.clean))
+	$(call message,,rm -f $(out_base)/test.out)
+
+# Generated .gitignore.
+#
+ifeq ($(out_base),$(src_base))
+$(driver): | $(out_base)/.gitignore
+
+$(out_base)/.gitignore: files := driver $(genf)
+$(clean): $(out_base)/.gitignore.clean
+
+$(call include,$(bld_root)/git/gitignore.make)
+endif
+
+# How to.
+#
+$(call include,$(bld_root)/dist.make)
+$(call include,$(bld_root)/meta/vc9proj.make)
+$(call include,$(bld_root)/meta/vc10proj.make)
+$(call include,$(bld_root)/meta/automake.make)
+
+$(call include,$(odb_rules))
+$(call include,$(bld_root)/cxx/cxx-d.make)
+$(call include,$(bld_root)/cxx/cxx-o.make)
+$(call include,$(bld_root)/cxx/o-e.make)
+
+# Dependencies.
+#
+$(call import,$(src_root)/libcommon/makefile)
diff --git a/common/wrapper/test.hxx b/common/wrapper/test.hxx
new file mode 100644
index 0000000..68a8750
--- /dev/null
+++ b/common/wrapper/test.hxx
@@ -0,0 +1,53 @@
+// file      : common/wrapper/test.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#ifndef TEST_HXX
+#define TEST_HXX
+
+#include <common/config.hxx> // HAVE_TR1_MEMORY
+
+#include <string>
+#include <memory> // std::auto_ptr
+#include <vector>
+
+#include <odb/core.hxx>
+#include <odb/nullable.hxx>
+
+#ifdef HAVE_TR1_MEMORY
+#  include <odb/tr1/memory.hxx>
+#endif
+
+using odb::nullable;
+
+typedef nullable<std::string> nullable_string;
+
+#ifdef HAVE_TR1_MEMORY
+typedef std::tr1::shared_ptr<std::string> tr1_nullable_string;
+#endif
+
+#pragma db object
+struct object
+{
+  #pragma db id auto
+  unsigned long id_;
+
+  std::auto_ptr<unsigned long> num;
+
+  #pragma db null
+  std::auto_ptr<std::string> str;
+
+  nullable_string nstr;
+  std::vector<nullable_string> nstrs;
+
+#ifdef HAVE_TR1_MEMORY
+  #pragma db null
+  tr1_nullable_string tr1_str;
+
+  #pragma db value_null
+  std::vector<tr1_nullable_string> tr1_strs;
+#endif
+};
+
+#endif // TEST_HXX
diff --git a/common/wrapper/test.std b/common/wrapper/test.std
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/common/wrapper/test.std
diff --git a/mysql/types/makefile b/mysql/types/makefile
index 4114128..2b17653 100644
--- a/mysql/types/makefile
+++ b/mysql/types/makefile
@@ -36,7 +36,7 @@ gen  := $(addprefix $(out_base)/,$(genf))
 $(gen): $(odb)
 $(gen): odb := $(odb)
 $(gen) $(dist): export odb_options += --database mysql --generate-schema \
---generate-query --cxx-prologue '\#include "traits.hxx"'
+--generate-query --hxx-prologue '\#include "traits.hxx"'
 
 $(gen): cpp_options := -I$(src_base)
 $(gen): $(common.l.cpp-options)