rosa/inc/alsk/edsl/op/impl/serial.h

#ifndef ALSK_ALSK_EDSL_OP_IMPL_SERIAL_H
#define ALSK_ALSK_EDSL_OP_IMPL_SERIAL_H

#include <utility>

#include "../traits.h"
#include "../../../skeleton/bone/serial.h"
#include "../../../skeleton/struct/struct.h"
#include "../../../skeleton/link/link.h"

namespace alsk {
namespace edsl {

template<typename Signature_, typename... Operands>
struct Serial: OperandBase {
	std::tuple<Operands...> operands;

	constexpr Serial(Operands... operands): operands{operands...} {}

	template<typename S>
	constexpr Serial(Serial<S, Operands...> const& o): operands{o.operands} {}

	template<typename S>
	constexpr Serial(Serial<S, Operands...>&& o): operands{std::move(o.operands)} {}

	using Signature = Signature_;

	using Struct    = S<alsk::Serial, typename Operands::Struct...>;
	using Links     = L<alsk::Serial, Signature, typename Operands::Links...>;

	template<typename S>
	constexpr void setup(S& skeleton) const {
		setup(skeleton, std::make_index_sequence<sizeof...(Operands)>());
	}

	template<typename S, std::size_t... indices>
	constexpr void setup(S& skeleton, std::index_sequence<indices...>) const {
		using Expander = int[];
		static_cast<void>(Expander{(OperandBase::setupFor(std::get<indices>(operands), skeleton.template task<indices>()), 0)...});
	}

	template<typename Signature>
	constexpr auto link() const&& {
		return Serial<Signature, Operands...>{std::move(*this)};
	}

	template<typename Signature>
	constexpr auto link() const& {
		return Serial<Signature, Operands...>{*this};
	}
};

namespace impl {

template<typename Lhs, std::size_t... lIndices, typename Rhs, std::size_t... rIndices>
constexpr auto mergeSerial(Lhs const& lhs, std::index_sequence<lIndices...>, Rhs const& rhs, std::index_sequence<rIndices...>) {
	return Serial<void(), std::tuple_element_t<lIndices, Lhs>..., std::tuple_element_t<rIndices, Rhs>...>{
		std::get<lIndices>(lhs)..., std::get<rIndices>(rhs)...
	};
}

template<typename Lhs, typename Rhs>
constexpr auto mergeSerial(Lhs const& lhs, Rhs const& rhs) {
	return mergeSerial(lhs, std::make_index_sequence<std::tuple_size<Lhs>{}>(),
										 rhs, std::make_index_sequence<std::tuple_size<Rhs>{}>());
}

template<typename T>
constexpr auto operandTuple(T const& t) {
	return std::make_tuple(t);
}

template<typename... Ts>
constexpr auto operandTuple(Serial<Ts...> const& s) noexcept {
	return s.operands;
}

template<typename...> struct SerialBuilder;

template<typename Arg, typename... Args>
struct SerialBuilder<Arg, Args...> {
	static constexpr auto build(Arg const& arg, Args const&... args) {
		return mergeSerial(operandTuple(arg), operandTuple(SerialBuilder<Args...>::build(args...)));
	}
};

template<typename Arg>
struct SerialBuilder<Arg> {
	static constexpr auto build(Arg const& arg) {
		return arg;
	}
};

}

template<typename... Args, std::enable_if_t<(sizeof...(Args) > 1) and allOperands<Args...>>* = nullptr>
constexpr auto serial(Args const&... args) {
	return impl::SerialBuilder<Args...>::build(args...);
}

template<
	typename Lhs, typename Rhs,
	std::enable_if_t<isOperand<Lhs> and isOperand<Rhs>>* = nullptr
	>
constexpr auto operator,(Lhs const& lhs, Rhs const& rhs) {
	return impl::mergeSerial(impl::operandTuple(lhs), impl::operandTuple(rhs));
}

template<
	typename Lhs, typename Rhs,
	std::enable_if_t<isOperand<Lhs> and isOperand<Rhs>>* = nullptr
	>
constexpr auto operator&(Lhs const& lhs, Rhs const& rhs) {
	return impl::mergeSerial(impl::operandTuple(lhs), impl::operandTuple(rhs));
}

}
}

#endif