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

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2.6 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_DETAIL_MAKE_EXPRESSION_TUPLE_H
#define SQLPP_DETAIL_MAKE_EXPRESSION_TUPLE_H
namespace sqlpp
{
namespace detail
{
template<typename Expr>
auto make_single_expression_tuple(Expr&& expr) -> typename std::enable_if<is_named_expression_t<typename std::decay<Expr>::type>::value, decltype(std::make_tuple(expr))>::type
{
return std::make_tuple(std::forward<Expr>(expr));
};
template<typename Expr>
auto make_single_expression_tuple(Expr&& expr) -> typename std::enable_if<is_select_flag_t<typename std::decay<Expr>::type>::value, std::tuple<>>::type
{
return {};
};
template<typename Tab>
auto make_single_expression_tuple(Tab&& tab) -> typename std::enable_if<is_table_t<typename std::decay<Tab>::type>::value, typename std::decay<Tab>::type::_all_of_t>::type
{
return {};
};
template<typename... Expr>
auto make_single_expression_tuple(std::tuple<Expr...>&& t) -> std::tuple<Expr...>
{
return t;
};
template<typename... Expr>
auto make_expression_tuple(Expr&&... expr) -> decltype(std::tuple_cat(make_single_expression_tuple(std::forward<Expr>(expr))...))
{
return std::tuple_cat(make_single_expression_tuple(std::forward<Expr>(expr))...);
};
}
}
#endif