Allow in() and not_in() to have zero arguments

This is then equivalent to in(value_list(some_empty_vector)) and
not_in(value_list(some_empty_vector):

tab.a.in() evaluates to false
tab.a.not_in() evaluates to true

include/sqlpp11/in.h

@@ -56,8 +56,6 @@ namespace sqlpp
     using _traits = make_traits<boolean, tag::is_expression, tag::is_selectable>;
     using _nodes = detail::type_vector<Operand, Args...>;
 
-    static_assert(sizeof...(Args) > 0, "in() requires at least one argument");
-
     using _auto_alias_t = in_alias_t;
 
     in_t(Operand operand, Args... args) : _operand(operand), _args(args...)
@@ -93,6 +91,19 @@ namespace sqlpp
     }
   };
 
+  template <typename Context, typename Operand>
+  struct serializer_t<Context, in_t<Operand>>
+  {
+    using _serialize_check = consistent_t;
+    using T = in_t<Operand>;
+
+    static Context& _(const T&, Context& context)
+    {
+      serialize(boolean_operand{false}, context);
+      return context;
+    }
+  };
+
   template <typename Container>
   struct value_list_t;
 
@@ -107,7 +118,7 @@ namespace sqlpp
       const auto& value_list = std::get<0>(t._args);
       if (value_list._container.empty())
       {
-        context << " 'operand in empty list' = 'false' ";
+        serialize(boolean_operand{false}, context);
       }
       else
       {

include/sqlpp11/not_in.h

@@ -56,8 +56,6 @@ namespace sqlpp
     using _traits = make_traits<boolean, tag::is_expression, tag::is_selectable>;
     using _nodes = detail::type_vector<Operand, Args...>;
 
-    static_assert(sizeof...(Args) > 0, "not_in() requires at least one argument");
-
     using _auto_alias_t = not_in_alias_t;
 
     not_in_t(Operand operand, Args... args) : _operand(operand), _args(args...)
@@ -93,6 +91,19 @@ namespace sqlpp
     }
   };
 
+  template <typename Context, typename Operand>
+  struct serializer_t<Context, not_in_t<Operand>>
+  {
+    using _serialize_check = consistent_t;
+    using T = not_in_t<Operand>;
+
+    static Context& _(const T&, Context& context)
+    {
+      serialize(boolean_operand{true}, context);
+      return context;
+    }
+  };
+
   template <typename Container>
   struct value_list_t;
 
@@ -107,7 +118,7 @@ namespace sqlpp
       const auto& value_list = std::get<0>(t._args);
       if (value_list._container.empty())
       {
-        context << " 'operand not in empty list' != 'false' ";
+        serialize(boolean_operand{true}, context);
       }
       else
       {

include/sqlpp11/result_row.h

@@ -63,6 +63,12 @@ namespace sqlpp
       {
         _field::operator()()._bind(target, index);
       }
+
+      template <typename Target>
+      void _post_bind(Target& target)
+      {
+        _field::operator()()._post_bind(target, index);
+      }
     };
 
     template <std::size_t index, typename AliasProvider, typename Db, typename... FieldSpecs>
@@ -91,6 +97,12 @@ namespace sqlpp
       {
         _multi_field::operator()()._bind(target);
       }
+
+      template <typename Target>
+      void _post_bind(Target& target)
+      {
+        _multi_field::operator()()._post_bind(target);
+      }
     };
 
     template <typename Db, std::size_t NextIndex, std::size_t... Is, typename... FieldSpecs>
@@ -117,6 +129,13 @@ namespace sqlpp
         using swallow = int[];
         (void)swallow{(result_field<Db, Is, FieldSpecs>::_bind(target), 0)...};
       }
+
+      template <typename Target>
+      void _post_bind(Target& target)
+      {
+        using swallow = int[];
+        (void)swallow{(result_field<Db, Is, FieldSpecs>::_post_bind(target), 0)...};
+      }
     };
   }
 
@@ -175,6 +194,12 @@ namespace sqlpp
     {
       _impl::_bind(target);
     }
+
+    template <typename Target>
+    void _post_bind(Target& target)
+    {
+      _impl::_post_bind(target);
+    }
   };
 
   template <typename Db, typename... FieldSpecs>
@@ -254,6 +279,19 @@ namespace sqlpp
         ++index;
       }
     }
+
+    template <typename Target>
+    void _post_bind(Target& target)
+    {
+      _impl::_post_bind(target);
+
+      std::size_t index = _field_index_sequence::_next_index;
+      for (const auto& field_name : _dynamic_field_names)
+      {
+        _dynamic_fields.at(field_name)._post_bind(target, index);
+        ++index;
+      }
+    }
   };
 
   template <typename T>