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sqlpp11/select_flag_list.h
2013-08-13 22:43:10 +02:00

111 lines
3.1 KiB
C++

/*
* Copyright (c) 2013, 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_FLAGS_H
#define SQLPP_SELECT_FLAGS_H
#include <sqlpp11/select_fwd.h>
#include <sqlpp11/type_traits.h>
#include <sqlpp11/detail/set.h>
#include <sqlpp11/detail/serialize_tuple.h>
#include <tuple>
#include <ostream>
namespace sqlpp
{
// standard select flags
struct all_t
{
struct _value_type
{
using _is_select_flag = tag_yes;
};
template<typename Db>
void serialize(std::ostream& os, const Db&) const
{
os << "ALL";
}
};
static constexpr all_t all = {};
struct distinct_t
{
struct _value_type
{
using _is_select_flag = tag_yes;
};
template<typename Db>
void serialize(std::ostream& os, const Db&) const
{
os << "DISTINCT";
}
};
static constexpr distinct_t distinct = {};
struct straight_join_t
{
struct _value_type
{
using _is_select_flag = tag_yes;
};
template<typename Db>
void serialize(std::ostream& os, const Db&) const
{
os << "STRAIGHT_JOIN";
}
};
static constexpr straight_join_t straight_join = {};
// select_flag_list_t
template<typename... Flag>
struct select_flag_list_t<std::tuple<Flag...>>
{
// check for duplicate order expressions
static_assert(not detail::has_duplicates<Flag...>::value, "at least one duplicate argument detected in select flag list");
// check for invalid order expressions
using _valid_flags = typename detail::make_set_if<is_select_flag_t, Flag...>::type;
static_assert(_valid_flags::size::value == sizeof...(Flag), "at least one argument is not a select flag in select flag list");
using _is_select_flag_list = tag_yes;
template<typename Db>
void serialize(std::ostream& os, Db& db) const
{
detail::serialize_tuple(os, db, _flags, ' ');
os << ' ';
}
std::tuple<Flag...> _flags;
};
}
#endif