sqlpp11/include/sqlpp11/extra_tables.h

/*
 * Copyright (c) 2013-2015, Roland Bock
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 *
 *   Redistributions in binary form must reproduce the above copyright notice, this
 *   list of conditions and the following disclaimer in the documentation and/or
 *   other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef SQLPP_EXTRA_TABLES_H
#define SQLPP_EXTRA_TABLES_H

#include <sqlpp11/type_traits.h>
#include <sqlpp11/logic.h>
#include <sqlpp11/policy_update.h>

namespace sqlpp
{
  template <typename... Tables>
  struct extra_tables_data_t
  {
    extra_tables_data_t()
    {
    }

    extra_tables_data_t(const extra_tables_data_t&) = default;
    extra_tables_data_t(extra_tables_data_t&&) = default;
    extra_tables_data_t& operator=(const extra_tables_data_t&) = default;
    extra_tables_data_t& operator=(extra_tables_data_t&&) = default;
    ~extra_tables_data_t() = default;
  };

  // EXTRA_TABLES
  template <typename... Tables>
  struct extra_tables_t
  {
    using _traits = make_traits<no_value_t, tag::is_extra_tables>;
    using _nodes = detail::type_vector<>;
    using _required_ctes = detail::make_joined_set_t<required_ctes_of<Tables>...>;
    using _extra_tables = detail::type_set<Tables...>;

    // Data
    using _data_t = extra_tables_data_t<Tables...>;

    // Member implementation with data and methods
    template <typename Policies>
    struct _impl_t
    {
      // workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
      _impl_t() = default;
      _impl_t(const _data_t& data) : _data(data)
      {
      }

      _data_t _data;
    };

    // Base template to be inherited by the statement
    template <typename Policies>
    struct _base_t
    {
      using _data_t = extra_tables_data_t<Tables...>;

      // workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
      template <typename... Args>
      _base_t(Args&&... args)
          : extra_tables{std::forward<Args>(args)...}
      {
      }

      _impl_t<Policies> extra_tables;
      _impl_t<Policies>& operator()()
      {
        return extra_tables;
      }
      const _impl_t<Policies>& operator()() const
      {
        return extra_tables;
      }

      template <typename T>
      static auto _get_member(T t) -> decltype(t.extra_tables)
      {
        return t.extra_tables;
      }

      using _consistency_check = consistent_t;
    };
  };

  // NO EXTRA TABLES YET
  struct no_extra_tables_t
  {
    using _traits = make_traits<no_value_t, tag::is_noop>;
    using _nodes = detail::type_vector<>;

    // Data
    using _data_t = no_data_t;

    // Member implementation with data and methods
    template <typename Policies>
    struct _impl_t
    {
      // workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
      _impl_t() = default;
      _impl_t(const _data_t& data) : _data(data)
      {
      }

      _data_t _data;
    };

    // Base template to be inherited by the statement
    template <typename Policies>
    struct _base_t
    {
      using _data_t = no_data_t;

      // workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2091069
      template <typename... Args>
      _base_t(Args&&... args)
          : no_extra_tables{std::forward<Args>(args)...}
      {
      }

      _impl_t<Policies> no_extra_tables;
      _impl_t<Policies>& operator()()
      {
        return no_extra_tables;
      }
      const _impl_t<Policies>& operator()() const
      {
        return no_extra_tables;
      }

      template <typename T>
      static auto _get_member(T t) -> decltype(t.no_extra_tables)
      {
        return t.no_extra_tables;
      }

      template <typename Check, typename T>
      using _new_statement_t = new_statement_t<Check::value, Policies, no_extra_tables_t, T>;

      // workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2173269
      //	  template <typename... T>
      //	  using _check = logic::all_t<is_table_t<T>::value...>;
      template <typename... T>
      struct _check : logic::all_t<is_table_t<T>::value...>
      {
      };

      using _consistency_check = consistent_t;

      template <typename... Tables>
      auto extra_tables(Tables... tables) const -> _new_statement_t<_check<Tables...>, extra_tables_t<Tables...>>
      {
        static_assert(_check<Tables...>::value, "at least one argument is not a table or join in extra_tables()");

        return _extra_tables_impl<void>(_check<Tables...>{}, tables...);
      }

    private:
      template <typename Database, typename... Tables>
      auto _extra_tables_impl(const std::false_type&, Tables... tables) const -> bad_statement;

      template <typename Database, typename... Tables>
      auto _extra_tables_impl(const std::true_type&, Tables...) const
          -> _new_statement_t<std::true_type, extra_tables_t<Tables...>>
      {
        static_assert(required_tables_of<extra_tables_t<Tables...>>::size::value == 0,
                      "at least one table depends on another table in extra_tables()");

        static constexpr std::size_t _number_of_tables = detail::sum(provided_tables_of<Tables>::size::value...);
        using _unique_tables = detail::make_joined_set_t<provided_tables_of<Tables>...>;
        // workaround for msvc bug https://connect.microsoft.com/VisualStudio/feedback/details/2173198
        //		using _unique_table_names = detail::transform_set_t<name_of, _unique_tables>;
        using _unique_table_names = detail::make_name_of_set_t<_unique_tables>;
        static_assert(_number_of_tables == _unique_tables::size::value,
                      "at least one duplicate table detected in extra_tables()");
        static_assert(_number_of_tables == _unique_table_names::size::value,
                      "at least one duplicate table name detected in extra_tables()");

        return {static_cast<const derived_statement_t<Policies>&>(*this), extra_tables_data_t<Tables...>{}};
      }
    };
  };

  // Interpreters
  template <typename Context, typename Database, typename... Tables>
  struct serializer_t<Context, extra_tables_data_t<Database, Tables...>>
  {
    using _serialize_check = serialize_check_of<Context, Tables...>;
    using T = extra_tables_data_t<Database, Tables...>;

    static Context& _(const T&, Context& context)
    {
      return context;
    }
  };
}

#endif