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sqlpp11/include/sqlpp11/field_spec.h
2014-07-25 15:20:19 +02:00

78 lines
3.0 KiB
C++

/*
* 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_FIELD_SPEC_H
#define SQLPP_FIELD_SPEC_H
#include <sqlpp11/multi_column.h>
namespace sqlpp
{
template<typename NameType, typename ValueType, bool CanBeNull, bool NullIsTrivialValue>
struct field_spec_t
{
using _traits = make_traits<ValueType, tag::noop,
typename std::conditional<CanBeNull, tag::can_be_null, void>::type,
typename std::conditional<NullIsTrivialValue, tag::null_is_trivial_value, void>::type
>;
using _recursive_traits = make_recursive_traits<>;
using _name_t = NameType;
};
template<typename AliasProvider, typename FieldSpecTuple>
struct multi_field_spec_t
{
};
namespace detail
{
template<typename Select, typename NamedExpr>
struct make_field_spec_impl
{
static constexpr bool _can_be_null = can_be_null_t<NamedExpr>::value;
static constexpr bool _depends_on_outer_table = detail::make_intersect_set_t<required_tables_of<NamedExpr>, typename Select::_used_outer_tables>::size::value > 0;
using type = field_spec_t<typename NamedExpr::_name_t,
value_type_of<NamedExpr>,
detail::any_t<_can_be_null, _depends_on_outer_table>::value,
null_is_trivial_value_t<NamedExpr>::value>;
};
template<typename Select, typename AliasProvider, typename... NamedExprs>
struct make_field_spec_impl<Select, multi_column_alias_t<AliasProvider, NamedExprs...>>
{
using type = multi_field_spec_t<AliasProvider, std::tuple<typename make_field_spec_impl<Select, NamedExprs>::type...>>;
};
}
template<typename Select, typename NamedExpr>
using make_field_spec_t = typename detail::make_field_spec_impl<Select, NamedExpr>::type;
}
#endif