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sqlpp11/include/sqlpp11/on.h

97 lines
3.5 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_ON_H
#define SQLPP_ON_H
#include <sqlpp11/type_traits.h>
#include <sqlpp11/interpret_tuple.h>
#include <sqlpp11/interpretable_list.h>
#include <sqlpp11/logic.h>
namespace sqlpp
{
template<typename Database, typename... Expressions>
struct on_t
{
using _traits = make_traits<no_value_t, tag::is_on>;
using _recursive_traits = make_recursive_traits<Expressions...>;
using _is_dynamic = is_database<Database>;
static_assert(_is_dynamic::value or sizeof...(Expressions), "at least one expression argument required in on()");
template<typename Expr>
void add(Expr expr)
{
static_assert(_is_dynamic::value, "on::add() must not be called for static on()");
static_assert(is_expression_t<Expr>::value, "invalid expression argument in on::add()");
using _serialize_check = sqlpp::serialize_check_t<typename Database::_serializer_context_t, Expr>;
_serialize_check::_();
using ok = logic::all_t<_is_dynamic::value, is_expression_t<Expr>::value, _serialize_check::type::value>;
_add_impl(expr, ok()); // dispatch to prevent compile messages after the static_assert
}
private:
template<typename Expr>
void _add_impl(Expr expr, const std::true_type&)
{
return _dynamic_expressions.emplace_back(expr);
}
template<typename Expr>
void _add_impl(Expr expr, const std::false_type&);
public:
std::tuple<Expressions...> _expressions;
interpretable_list_t<Database> _dynamic_expressions;
};
template<typename Context, typename Database, typename... Expressions>
struct serializer_t<Context, on_t<Database, Expressions...>>
{
using _serialize_check = serialize_check_of<Context, Expressions...>;
using T = on_t<Database, Expressions...>;
static Context& _(const T& t, Context& context)
{
if (sizeof...(Expressions) == 0 and t._dynamic_expressions.empty())
return context;
context << " ON ";
interpret_tuple(t._expressions, " AND ", context);
if (sizeof...(Expressions) and not t._dynamic_expressions.empty())
context << " AND ";
interpret_list(t._dynamic_expressions, " AND ", context);
return context;
}
};
}
#endif