sqlpp11/include/sqlpp11/select_flag_list.h

/*
 * Copyright (c) 2013-2014, 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_SELECT_FLAG_LIST_H
#define SQLPP_SELECT_FLAG_LIST_H

#include <tuple>
#include <sqlpp11/type_traits.h>
#include <sqlpp11/no_data.h>
#include <sqlpp11/select_flags.h>
#include <sqlpp11/detail/type_set.h>
#include <sqlpp11/interpret_tuple.h>
#include <sqlpp11/policy_update.h>

namespace sqlpp
{
	// SELECTED FLAGS DATA
	template<typename Database, typename... Flags>
		struct select_flag_list_data_t
		{
			select_flag_list_data_t(Flags... flags):
				_flags(flags...)
			{}

			select_flag_list_data_t(const select_flag_list_data_t&) = default;
			select_flag_list_data_t(select_flag_list_data_t&&) = default;
			select_flag_list_data_t& operator=(const select_flag_list_data_t&) = default;
			select_flag_list_data_t& operator=(select_flag_list_data_t&&) = default;
			~select_flag_list_data_t() = default;

			std::tuple<Flags...> _flags;
			interpretable_list_t<Database> _dynamic_flags;
		};

	// SELECT FLAGS
	template<typename Database, typename... Flags>
		struct select_flag_list_t
		{
			using _traits = make_traits<no_value_t, tag::is_select_flag_list>;
			using _recursive_traits = make_recursive_traits<Flags...>;

			using _is_dynamic = is_database<Database>;

			// Data
			using _data_t = select_flag_list_data_t<Database, Flags...>;

			// Member implementation with data and methods
			template<typename Policies>
				struct _impl_t
				{
					template<typename Flag>
						void add_ntc(Flag flag)
						{
							add<Flag, std::false_type>(flag);
						}

					template<typename Flag, typename TableCheckRequired = std::true_type>
						void add(Flag flag)
						{
							static_assert(_is_dynamic::value, "select_flags::add() must not be called for static select flags");
							static_assert(is_select_flag_t<Flag>::value, "invalid select flag argument in select_flags::add()");
							static_assert(TableCheckRequired::value or Policies::template _no_unknown_tables<Flag>::value, "flag uses tables unknown to this statement in select_flags::add()");
							using _serialize_check = sqlpp::serialize_check_t<typename Database::_serializer_context_t, Flag>;
							_serialize_check::_();

							using ok = detail::all_t<_is_dynamic::value, is_select_flag_t<Flag>::value, _serialize_check::type::value>;

							_add_impl(flag, ok()); // dispatch to prevent compile messages after the static_assert
						}

				private:
					template<typename Flag>
						void _add_impl(Flag flag, const std::true_type&)
						{
							return _data._dynamic_flags.emplace_back(flag);
						}

					template<typename Flag>
						void _add_impl(Flag flag, const std::false_type&);
				public:
					_data_t _data;
				};

			// Base template to be inherited by the statement
			template<typename Policies>
				struct _base_t
				{
					using _data_t = select_flag_list_data_t<Database, Flags...>;

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

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

					using _consistency_check = consistent_t;
				};

		};

	struct no_select_flag_list_t
	{
		using _traits = make_traits<no_value_t, tag::is_noop>;
		using _recursive_traits = make_recursive_traits<>;

		// Data
		using _data_t = no_data_t;

		// Member implementation with data and methods
		template<typename Policies>
			struct _impl_t
			{
				_data_t _data;
			};

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

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

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

				using _database_t = typename Policies::_database_t;

				template<typename... T>
					using _check = detail::all_t<is_select_flag_t<T>::value...>;

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

				using _consistency_check = consistent_t;

				template<typename... Flags>
					auto flags(Flags... flags) const
					-> _new_statement_t<_check<Flags...>, select_flag_list_t<void, Flags...>>
					{
						static_assert(_check<Flags...>::value, "at least one argument is not a select flag in select flag list");

						return _flags_impl<void>(_check<Flags...>{}, flags...);
					}

				template<typename... Flags>
					auto dynamic_flags(Flags... flags) const
					-> _new_statement_t<_check<Flags...>, select_flag_list_t<_database_t, Flags...>>
					{
						static_assert(not std::is_same<_database_t, void>::value, "dynamic_flags must not be called in a static statement");
						static_assert(_check<Flags...>::value, "at least one argument is not a select flag in select flag list");

						return _flags_impl<_database_t>(_check<Flags...>{}, flags...);
					}

			private:
				template<typename Database, typename... Flags>
					auto _flags_impl(const std::false_type&, Flags... flags) const
					-> bad_statement;

				template<typename Database, typename... Flags>
					auto _flags_impl(const std::true_type&, Flags... flags) const
					-> _new_statement_t<std::true_type, select_flag_list_t<Database, Flags...>>
					{
						static_assert(not detail::has_duplicates<Flags...>::value, "at least one duplicate argument detected in select flag list");

						return { static_cast<const derived_statement_t<Policies>&>(*this), select_flag_list_data_t<Database, Flags...>{flags...} };
					}

			};
	};


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

			static Context& _(const T& t, Context& context)
			{
				interpret_tuple(t._flags, ' ', context);
				if (sizeof...(Flags))
					context << ' ';
				interpret_list(t._dynamic_flags, ',', context);
				if (not t._dynamic_flags.empty())
					context << ' ';
				return context;
			}
		};


}

#endif