serenity/AK/TypeList.h
Brian Gianforcaro 1682f0b760 Everything: Move to SPDX license identifiers in all files.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.

See: https://spdx.dev/resources/use/#identifiers

This was done with the `ambr` search and replace tool.

 ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
2021-04-22 11:22:27 +02:00

74 lines
1.9 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/StdLibExtras.h>
namespace AK {
template<typename... Types>
struct TypeList;
template<unsigned Index, typename List>
struct TypeListElement;
template<unsigned Index, typename Head, typename... Tail>
struct TypeListElement<Index, TypeList<Head, Tail...>>
: TypeListElement<Index - 1, TypeList<Tail...>> {
};
template<typename Head, typename... Tail>
struct TypeListElement<0, TypeList<Head, Tail...>> {
using Type = Head;
};
template<typename... Types>
struct TypeList {
static constexpr unsigned size = sizeof...(Types);
template<unsigned N>
using Type = typename TypeListElement<N, TypeList<Types...>>::Type;
};
template<typename T>
struct TypeWrapper {
using Type = T;
};
template<typename List, typename F, unsigned... Indexes>
constexpr void for_each_type_impl(F&& f, IndexSequence<Indexes...>)
{
(forward<F>(f)(TypeWrapper<typename List::template Type<Indexes>> {}), ...);
}
template<typename List, typename F>
constexpr void for_each_type(F&& f)
{
for_each_type_impl<List>(forward<F>(f), MakeIndexSequence<List::size> {});
}
template<typename ListA, typename ListB, typename F, unsigned... Indexes>
constexpr void for_each_type_zipped_impl(F&& f, IndexSequence<Indexes...>)
{
(forward<F>(f)(TypeWrapper<typename ListA::template Type<Indexes>> {}, TypeWrapper<typename ListB::template Type<Indexes>> {}), ...);
}
template<typename ListA, typename ListB, typename F>
constexpr void for_each_type_zipped(F&& f)
{
static_assert(ListA::size == ListB::size, "Can't zip TypeLists that aren't the same size!");
for_each_type_zipped_impl<ListA, ListB>(forward<F>(f), MakeIndexSequence<ListA::size> {});
}
}
using AK::for_each_type;
using AK::for_each_type_zipped;
using AK::TypeList;
using AK::TypeListElement;
using AK::TypeWrapper;