You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

275 lines
7.1 KiB

/*
* Copyright 2014 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef FRUIT_META_VECTOR_H
#define FRUIT_META_VECTOR_H
#include <fruit/impl/meta/basics.h>
#include <fruit/impl/meta/eval.h>
#include <fruit/impl/meta/fold.h>
#include <fruit/impl/meta/logical_operations.h>
#include <fruit/impl/meta/numeric_operations.h>
#include <functional>
namespace fruit {
namespace impl {
namespace meta {
// Used to pass around a Vector<Types...>, no meaning per se.
template <typename... Types>
struct Vector {};
// Using ConsVector(MetaExpr...) instead of Vector<MetaExpr...> in a meta-expression allows the
// types to be evaluated. Avoid using Vector<...> directly in a meta-expression, unless you're sure
// that the arguments have already been evaluated (e.g. if Args... are arguments of a metafunction,
// Vector<Args...> is ok but Vector<MyFunction(Args)...> is wrong.
struct ConsVector {
template <typename... Types>
struct apply {
using type = Vector<Types...>;
};
};
struct GenerateIntSequenceEvenHelper {
template <typename Half>
struct apply;
template <int... ns>
struct apply<Vector<Int<ns>...>> {
using type = Vector<Int<ns>..., Int<sizeof...(ns) + ns>...>;
};
};
struct GenerateIntSequenceOddHelper {
template <typename Half>
struct apply;
template <int... ns>
struct apply<Vector<Int<ns>...>> {
using type = Vector<Int<ns>..., Int<sizeof...(ns)>, Int<sizeof...(ns) + 1 + ns>...>;
};
};
struct GenerateIntSequence {
template <typename N>
struct apply {
using type = If(Bool<(N::value % 2) == 0>, GenerateIntSequenceEvenHelper(GenerateIntSequence(Int<N::value / 2>)),
GenerateIntSequenceOddHelper(GenerateIntSequence(Int<N::value / 2>)));
};
};
template <>
struct GenerateIntSequence::apply<Int<0>> {
using type = Vector<>;
};
template <>
struct GenerateIntSequence::apply<Int<1>> {
using type = Vector<Int<0>>;
};
struct IsInVector {
template <typename T>
struct AlwaysFalseBool {
constexpr static bool value = false;
};
template <bool... bs>
struct BoolVector;
template <typename T, typename V>
struct apply;
template <typename T, typename... Ts>
struct apply<T, Vector<Ts...>> {
using type = Bool<
!std::is_same<BoolVector<AlwaysFalseBool<Ts>::value...>, BoolVector<std::is_same<T, Ts>::value...>>::value>;
};
};
struct IsVectorContained {
template <typename V1, typename V2>
struct apply;
template <typename T>
struct AlwaysTrueBool {
constexpr static bool value = true;
};
template <bool... bs>
struct BoolVector;
template <typename... Ts, typename V2>
struct apply<Vector<Ts...>, V2> {
using type = Bool<std::is_same<BoolVector<AlwaysTrueBool<Ts>::value...>,
BoolVector<Id<typename IsInVector::template apply<Ts, V2>::type>::value...>>::value>;
};
};
struct VectorSize {
template <typename V>
struct apply;
template <typename... Ts>
struct apply<Vector<Ts...>> {
using type = Int<sizeof...(Ts)>;
};
};
struct PushFront {
template <typename V, typename T>
struct apply;
template <typename T, typename... Ts>
struct apply<Vector<Ts...>, T> {
using type = Vector<T, Ts...>;
};
};
struct PushBack {
template <typename V, typename T>
struct apply;
template <typename T, typename... Ts>
struct apply<Vector<Ts...>, T> {
using type = Vector<Ts..., T>;
};
};
struct ConcatVectors {
template <typename V1, typename V2>
struct apply;
template <typename... Ts, typename... Us>
struct apply<Vector<Ts...>, Vector<Us...>> {
using type = Vector<Ts..., Us...>;
};
};
struct TransformVector {
template <typename V, typename F>
struct apply;
template <typename... Ts, typename F>
struct apply<Vector<Ts...>, F> {
using type = Vector<Eval<typename F::template apply<Ts>::type>...>;
};
};
struct ReplaceInVectorHelper {
template <typename ToReplace, typename NewElem, typename T>
struct apply {
using type = T;
};
template <typename ToReplace, typename NewElem>
struct apply<ToReplace, NewElem, ToReplace> {
using type = NewElem;
};
};
struct ReplaceInVector {
template <typename V, typename ToReplace, typename NewElem>
struct apply {
using type = TransformVector(V, PartialCall(ReplaceInVectorHelper, ToReplace, NewElem));
};
};
// If V is Vector<T1, ..., Tn> this calculates F(InitialValue, F(T1, F(..., F(Tn) ...))).
// If V is Vector<> this returns InitialValue.
struct FoldVector {
template <typename V, typename F, typename InitialValue>
struct apply;
template <typename... Ts, typename F, typename InitialValue>
struct apply<Vector<Ts...>, F, InitialValue> {
using type = Fold(F, InitialValue, Ts...);
};
};
template <typename Unused>
using AlwaysVoidPtr = void*;
// Returns a copy of V but without the first N elements.
// N must be at least 0 and at most VectorSize(V).
struct VectorRemoveFirstN {
template <typename V, typename N, typename Indexes = Eval<GenerateIntSequence(N)>>
struct apply;
template <typename... Types, typename N, typename... Indexes>
struct apply<Vector<Types...>, N, Vector<Indexes...>> {
template <typename... RemainingTypes>
static Vector<RemainingTypes...> f(AlwaysVoidPtr<Indexes>..., RemainingTypes*...);
using type = decltype(f((Types*)nullptr...));
};
};
struct VectorEndsWith {
template <typename V, typename T>
struct apply {
using N = Int<Eval<VectorSize(V)>::value - 1>;
using type = IsSame(VectorRemoveFirstN(V, N), Vector<T>);
};
template <typename T>
struct apply<Vector<>, T> {
using type = Bool<false>;
};
};
// Removes all None elements from the vector.
// O(n) instantiations.
struct VectorRemoveNone {
template <typename V>
struct apply {
using type = Vector<>;
};
template <typename T, typename... Ts>
struct apply<Vector<T, Ts...>> {
using type = PushFront(VectorRemoveNone(Vector<Ts...>), T);
};
template <typename... Ts>
struct apply<Vector<None, Ts...>> {
using type = VectorRemoveNone(Vector<Ts...>);
};
};
struct ConstructErrorWithArgVectorHelper {
template <typename ErrorTag, typename ArgsVector, typename... OtherArgs>
struct apply;
template <typename ErrorTag, typename... Args, typename... OtherArgs>
struct apply<ErrorTag, Vector<Args...>, OtherArgs...> {
using type = ConstructError(ErrorTag, OtherArgs..., Args...);
};
};
struct ConstructErrorWithArgVector {
template <typename ErrorTag, typename ArgsVector, typename... OtherArgs>
struct apply {
using type = ConstructErrorWithArgVectorHelper(ErrorTag, VectorRemoveNone(ArgsVector), OtherArgs...);
};
};
} // namespace meta
} // namespace impl
} // namespace fruit
#endif // FRUIT_META_VECTOR_H