sqlpp11/include/sqlpp11/max.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_MAX_H
#define SQLPP_MAX_H

#include <sqlpp11/type_traits.h>

namespace sqlpp
{
	template<typename Expr>
		struct max_t: public value_type_of<Expr>::template expression_operators<max_t<Expr>>,
		public alias_operators<max_t<Expr>>
	{
		using _traits = make_traits<value_type_of<Expr>, ::sqlpp::tag::expression, ::sqlpp::tag::named_expression>;
		using _recursive_traits = make_recursive_traits<Expr>;

		static_assert(is_expression_t<Expr>::value, "max() requires a value expression as argument");

		struct _name_t
		{
			static constexpr const char* _get_name() { return "MAX"; }
			template<typename T>
				struct _member_t
				{
					T max;
					T& operator()() { return max; }
					const T& operator()() const { return max; }
				};
		};

		max_t(Expr expr):
			_expr(expr)
		{}

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

		Expr _expr;
	};

	template<typename Context, typename Expr>
		struct serializer_t<Context, max_t<Expr>>
		{
			using T = max_t<Expr>;

			static Context& _(const T& t, Context& context)
			{
				context << "MAX(";
				serialize(t._expr, context);
				context << ")";
				return context;
			}
		};

	template<typename T>
		auto max(T t) -> max_t<wrap_operand_t<T>>
		{
			static_assert(is_expression_t<wrap_operand_t<T>>::value, "max() requires a value expression as argument");
			return { t };
		}

}

#endif