[llvm] 2d1f2ba - Revert "[ADT] Add new type traits for type pack indexes"
Stella Stamenova via llvm-commits
llvm-commits at lists.llvm.org
Mon May 17 20:27:16 PDT 2021
Author: Stella Stamenova
Date: 2021-05-17T20:26:59-07:00
New Revision: 2d1f2ba7d51689de231794cf3dd74257aeccd315
URL: https://github.com/llvm/llvm-project/commit/2d1f2ba7d51689de231794cf3dd74257aeccd315
DIFF: https://github.com/llvm/llvm-project/commit/2d1f2ba7d51689de231794cf3dd74257aeccd315.diff
LOG: Revert "[ADT] Add new type traits for type pack indexes"
This reverts commit a6d3987b8ef3b7616f0835b89515c4264f2a7a64.
Added:
Modified:
llvm/include/llvm/ADT/PointerUnion.h
llvm/include/llvm/ADT/STLExtras.h
llvm/unittests/ADT/STLExtrasTest.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/ADT/PointerUnion.h b/llvm/include/llvm/ADT/PointerUnion.h
index 5c3ef01f1b05..c39691061b72 100644
--- a/llvm/include/llvm/ADT/PointerUnion.h
+++ b/llvm/include/llvm/ADT/PointerUnion.h
@@ -64,6 +64,21 @@ namespace pointer_union_detail {
return std::min<int>({PointerLikeTypeTraits<Ts>::NumLowBitsAvailable...});
}
+ /// Find the index of a type in a list of types. TypeIndex<T, Us...>::Index
+ /// is the index of T in Us, or sizeof...(Us) if T does not appear in the
+ /// list.
+ template <typename T, typename ...Us> struct TypeIndex;
+ template <typename T, typename ...Us> struct TypeIndex<T, T, Us...> {
+ static constexpr int Index = 0;
+ };
+ template <typename T, typename U, typename... Us>
+ struct TypeIndex<T, U, Us...> {
+ static constexpr int Index = 1 + TypeIndex<T, Us...>::Index;
+ };
+ template <typename T> struct TypeIndex<T> {
+ static constexpr int Index = 0;
+ };
+
/// Find the first type in a list of types.
template <typename T, typename...> struct GetFirstType {
using type = T;
@@ -130,7 +145,6 @@ namespace pointer_union_detail {
/// P = (float*)0;
/// Y = P.get<float*>(); // ok.
/// X = P.get<int*>(); // runtime assertion failure.
-/// PointerUnion<int*, int*> Q; // compile time failure.
template <typename... PTs>
class PointerUnion
: public pointer_union_detail::PointerUnionMembers<
@@ -139,14 +153,12 @@ class PointerUnion
void *, pointer_union_detail::bitsRequired(sizeof...(PTs)), int,
pointer_union_detail::PointerUnionUIntTraits<PTs...>>,
0, PTs...> {
- static_assert(TypesAreDistinct<PTs...>(),
- "PointerUnion alternative types cannot be repeated");
// The first type is special because we want to directly cast a pointer to a
// default-initialized union to a pointer to the first type. But we don't
// want PointerUnion to be a 'template <typename First, typename ...Rest>'
// because it's much more convenient to have a name for the whole pack. So
// split off the first type here.
- using First = TypeAtIndex<0, PTs...>;
+ using First = typename pointer_union_detail::GetFirstType<PTs...>::type;
using Base = typename PointerUnion::PointerUnionMembers;
public:
@@ -163,7 +175,10 @@ class PointerUnion
/// Test if the Union currently holds the type matching T.
template <typename T> bool is() const {
- return this->Val.getInt() == FirstIndexOfType<T, PTs...>{};
+ constexpr int Index = pointer_union_detail::TypeIndex<T, PTs...>::Index;
+ static_assert(Index < sizeof...(PTs),
+ "PointerUnion::is<T> given type not in the union");
+ return this->Val.getInt() == Index;
}
/// Returns the value of the specified pointer type.
diff --git a/llvm/include/llvm/ADT/STLExtras.h b/llvm/include/llvm/ADT/STLExtras.h
index fad62a5f7c9b..182451c25e32 100644
--- a/llvm/include/llvm/ADT/STLExtras.h
+++ b/llvm/include/llvm/ADT/STLExtras.h
@@ -144,60 +144,6 @@ template <typename ReturnType, typename... Args>
struct function_traits<ReturnType (&)(Args...), false>
: public function_traits<ReturnType (*)(Args...)> {};
-namespace detail {
-template <typename T, typename... Ts>
-constexpr size_t getFirstIndexOfTypeImpl() {
- constexpr bool Matches[] = {false, std::is_same<T, Ts>{}...};
- // TODO: use llvm::find once it's constexpr (std::find is constexpr in C++20)
- for (size_t I = 1; I <= sizeof...(Ts); ++I)
- if (Matches[I])
- return I - 1;
- return sizeof...(Ts);
-}
-template <typename T, typename... Ts> constexpr size_t getFirstIndexOfType() {
- constexpr size_t Index = getFirstIndexOfTypeImpl<T, Ts...>();
- static_assert(Index != sizeof...(Ts),
- "type T is not present in type pack Ts");
- return Index;
-}
-template <typename... Ts> static constexpr bool areTypesDistinct() {
- constexpr size_t IndexOf[] = {0, getFirstIndexOfType<Ts, Ts...>()...};
- // TODO: use llvm::find once it's constexpr (std::find is constexpr in C++20)
- for (size_t I = 1; I <= sizeof...(Ts); ++I)
- if (I - 1 != IndexOf[I])
- return false;
- return true;
-}
-} // namespace detail
-
-/// Determine if all types in Ts are distinct.
-///
-/// Useful to statically assert when Ts is intended to describe a non-multi set
-/// of types.
-template <typename... Ts>
-using TypesAreDistinct =
- std::integral_constant<bool, detail::areTypesDistinct<Ts...>()>;
-
-/// Find the first index where a type appears in a list of types.
-///
-/// FirstIndexOfType<T, Ts...>::value is the first index of T in Ts.
-///
-/// Typically only meaningful when it is otherwise statically known that the
-/// type pack has no duplicate types. This should be guaranteed explicitly with
-/// static_assert(TypesAreDistinct<Ts...>{}).
-///
-/// It is a compile-time error to instantiate when T is not present in Ts, i.e.
-/// if is_one_of<T, Ts...>::value is false.
-template <typename T, typename... Ts>
-using FirstIndexOfType =
- std::integral_constant<size_t, detail::getFirstIndexOfType<T, Ts...>()>;
-
-/// Find the type at a given index in a list of types.
-///
-/// TypeAtIndex<I, Ts...> is the type at index I in Ts.
-template <size_t I, typename... Ts>
-using TypeAtIndex = std::tuple_element_t<I, std::tuple<Ts...>>;
-
//===----------------------------------------------------------------------===//
// Extra additions to <functional>
//===----------------------------------------------------------------------===//
diff --git a/llvm/unittests/ADT/STLExtrasTest.cpp b/llvm/unittests/ADT/STLExtrasTest.cpp
index a80c6ce77306..862653055417 100644
--- a/llvm/unittests/ADT/STLExtrasTest.cpp
+++ b/llvm/unittests/ADT/STLExtrasTest.cpp
@@ -711,40 +711,4 @@ TEST(STLExtras, MoveRange) {
EXPECT_EQ(V4.size(), 4U);
EXPECT_TRUE(llvm::all_of(V4, HasVal));
}
-
-TEST(STLExtrasTest, TypesAreDistinct) {
- EXPECT_TRUE((llvm::TypesAreDistinct<>::value));
- EXPECT_TRUE((llvm::TypesAreDistinct<int>::value));
- EXPECT_FALSE((llvm::TypesAreDistinct<int, int>::value));
- EXPECT_TRUE((llvm::TypesAreDistinct<int, float>::value));
- EXPECT_FALSE((llvm::TypesAreDistinct<int, float, int>::value));
- EXPECT_TRUE((llvm::TypesAreDistinct<int, float, double>::value));
- EXPECT_FALSE((llvm::TypesAreDistinct<int, float, double, float>::value));
- EXPECT_TRUE((llvm::TypesAreDistinct<int, int *>::value));
- EXPECT_TRUE((llvm::TypesAreDistinct<int, int &>::value));
- EXPECT_TRUE((llvm::TypesAreDistinct<int, int &&>::value));
- EXPECT_TRUE((llvm::TypesAreDistinct<int, const int>::value));
-}
-
-TEST(STLExtrasTest, FirstIndexOfType) {
- EXPECT_EQ((llvm::FirstIndexOfType<int, int>::value), 0u);
- EXPECT_EQ((llvm::FirstIndexOfType<int, int, int>::value), 0u);
- EXPECT_EQ((llvm::FirstIndexOfType<int, float, int>::value), 1u);
- EXPECT_EQ((llvm::FirstIndexOfType<int const *, float, int, int const *,
- const int>::value),
- 2u);
-}
-
-TEST(STLExtrasTest, TypeAtIndex) {
- EXPECT_TRUE((std::is_same<int, llvm::TypeAtIndex<0, int>>::value));
- EXPECT_TRUE((std::is_same<int, llvm::TypeAtIndex<0, int, float>>::value));
- EXPECT_TRUE((std::is_same<float, llvm::TypeAtIndex<1, int, float>>::value));
- EXPECT_TRUE(
- (std::is_same<float, llvm::TypeAtIndex<1, int, float, double>>::value));
- EXPECT_TRUE(
- (std::is_same<float, llvm::TypeAtIndex<1, int, float, double>>::value));
- EXPECT_TRUE(
- (std::is_same<double, llvm::TypeAtIndex<2, int, float, double>>::value));
-}
-
} // namespace
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