serenity/AK/TypeList.h
Linus Groh a8ac8c6a8f AK: Add missing 'template' keywords in TypeList
This caused the AK build to be broken on OpenBSD (and possibly other
platforms / compiler versions).
Fixes #4692.
2020-12-31 16:16:07 +01:00

94 lines
3.1 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. 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.
*/
#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;