Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[ADT] Backport std::to_underlying from C++23 #70681

Merged
merged 6 commits into from
Oct 30, 2023
Merged

[ADT] Backport std::to_underlying from C++23 #70681

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
a83117a
[STLExtras] Backport std::to_underlying from C++23
Endilll Oct 30, 2023
1fdc702
Run clang-format
Endilll Oct 30, 2023
a6c4963
Move changes from STLExtras to STLForwardCompat
Endilll Oct 30, 2023
c1df3bc
Add description of function
Endilll Oct 30, 2023
daef3cc
Remove unnecessary `typename` keyword
Endilll Oct 30, 2023
3e41646
Run clang-format
Endilll Oct 30, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions llvm/include/llvm/ADT/STLForwardCompat.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -60,6 +60,13 @@ auto transformOptional(std::optional<T> &&O, const Function &F)
return std::nullopt;
}

/// Returns underlying integer value of an enum. Backport of C++23
/// std::to_underlying.
template <typename Enum>
[[nodiscard]] constexpr std::underlying_type_t<Enum> to_underlying(Enum E) {
return static_cast<std::underlying_type_t<Enum>>(E);
}

} // namespace llvm

#endif // LLVM_ADT_STLFORWARDCOMPAT_H
17 changes: 17 additions & 0 deletions llvm/unittests/ADT/STLForwardCompatTest.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -119,4 +119,21 @@ TEST(TransformTest, MoveTransformLlvm) {
EXPECT_EQ(0u, MoveOnly::Destructions);
}

TEST(TransformTest, ToUnderlying) {
enum E { A1 = 0, B1 = -1 };
static_assert(llvm::to_underlying(A1) == 0);
static_assert(llvm::to_underlying(B1) == -1);

enum E2 : unsigned char { A2 = 0, B2 };
static_assert(
std::is_same_v<unsigned char, decltype(llvm::to_underlying(A2))>);
static_assert(llvm::to_underlying(A2) == 0);
static_assert(llvm::to_underlying(B2) == 1);

enum class E3 { A3 = -1, B3 };
static_assert(std::is_same_v<int, decltype(llvm::to_underlying(E3::A3))>);
kuhar marked this conversation as resolved.
Show resolved Hide resolved
static_assert(llvm::to_underlying(E3::A3) == -1);
static_assert(llvm::to_underlying(E3::B3) == 0);
}

} // namespace