Merge pull request #9 from beman-project/neatudarius/P3168R1

Implement P3168R1: Give std::optional Range Support
bemanproject · Jun 19, 2024 · 6666e03 · 6666e03
2 parents ce7d23c + 77fb8da
commit 6666e03
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Showing 10 changed files with 409 additions and 129 deletions.
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -34,15 +34,6 @@ jobs:
           cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" "
           }
 
-        - {
-          name: "Ubuntu Clang 19",
-          os: ubuntu-24.04,
-          toolchain: "clang-19-toolchain.cmake",
-          clang_version: 19,
-          installed_clang_version: 14,
-          cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" "
-          }
-
         - {
             name: "Ubuntu GCC 13",
             os: ubuntu-24.04,
@@ -68,9 +59,13 @@ jobs:
 
       - uses: seanmiddleditch/gha-setup-ninja@master
 
+      - name: Activate verbose shell
+        run: set -x
+
       - name: Install LLVM+Clang
         if: startsWith(matrix.config.os, 'ubuntu-')
         run: |
+          set -x
           cat /etc/lsb-release
           sudo apt-get remove clang-${{matrix.config.installed_clang_version}} \
             lldb-${{matrix.config.installed_clang_version}} \
@@ -105,6 +100,7 @@ jobs:
 
       - name: Configure
         run: |
+          rm -rf .build
           mkdir -p .build
           cd .build
           echo ${{ matrix.config.cmake_args }}

diff --git a/include/Beman/Optional26/optional.hpp b/include/Beman/Optional26/optional.hpp
@@ -1,6 +1,6 @@
-// beman/optional/optional.h                                            -*-C++-*-
-#ifndef BEMAN_OPTIONAL26_OPTIONAL
-#define BEMAN_OPTIONAL26_OPTIONAL
+// include/Beman/Optional26/optional.hpp                                            -*-C++-*-
+#ifndef BEMAN_OPTIONAL26_OPTIONAL_HPP
+#define BEMAN_OPTIONAL26_OPTIONAL_HPP
 
 /*
 22.5.2 Header <optional> synopsis[optional.syn]
@@ -165,10 +165,13 @@ namespace std {
 */
 
 #include <compare>
-#include <utility>
+#if defined(__cpp_lib_format_ranges)
+#include <format>
+#endif
 #include <functional>
-#include <type_traits>
 #include <ranges>
+#include <type_traits>
+#include <utility>
 
 namespace beman::optional {
 
@@ -202,22 +205,22 @@ template <class T>
 class optional;
 
 } // namespace beman::optional
+
 namespace std {
+// Since P3168R1: Give std::optional Range Support.
 template <typename T>
 inline constexpr bool ranges::enable_view<beman::optional::optional<T>> = true;
 
-template <typename T>
-inline constexpr bool ranges::enable_view<beman::optional::optional<T&>> = true;
-
-template <typename T>
-inline constexpr bool ranges::enable_borrowed_range<beman::optional::optional<T*>> = true;
-
-template <typename T>
-inline constexpr bool ranges::enable_borrowed_range<beman::optional::optional<std::reference_wrapper<T>>> = true;
-
+// TODO: document why this is needed.
 template <typename T>
 inline constexpr bool ranges::enable_borrowed_range<beman::optional::optional<T&>> = true;
 
+// Since P3168R1: Give std::optional Range Support.
+#if defined(__cpp_lib_format_ranges)
+template <class T>
+inline constexpr auto format_kind<beman::optional::optional<T>> = range_format::disabled;
+#endif
+
 } // namespace std
 
 namespace beman::optional {
@@ -309,6 +312,11 @@ class optional {
     }
 
   public:
+    using value_type = T;
+    // Since P3168R1: Give std::optional Range Support.
+    using iterator       = T*;       // see [optional.iterators]
+    using const_iterator = const T*; // see [optional.iterators]
+
     constexpr optional() noexcept
         requires std::is_default_constructible_v<T>
     = default;
@@ -675,6 +683,13 @@ class optional {
         swap(engaged, rhs.engaged);
     }
 
+    // Since P3168R1: Give std::optional Range Support.
+    // [optional.iterators], iterator support
+    constexpr iterator       begin() noexcept { return has_value() ? std::addressof(value_) : nullptr; };
+    constexpr const_iterator begin() const noexcept { return has_value() ? std::addressof(value_) : nullptr; };
+    constexpr iterator       end() noexcept { return begin() + has_value(); }
+    constexpr const_iterator end() const noexcept { return begin() + has_value(); }
+
     /// Returns a pointer to the stored value
     constexpr const T* operator->() const { return std::addressof(value_); }
 
@@ -699,36 +714,6 @@ class optional {
         }
         engaged = false;
     }
-    using iterator       = T*;
-    using const_iterator = const T*;
-
-    // [optional.iterators], iterator support
-    constexpr T* begin() noexcept {
-        if (has_value()) {
-            return std::addressof(value_);
-        } else {
-            return nullptr;
-        }
-    }
-    constexpr const T* begin() const noexcept {
-        if (has_value()) {
-            return std::addressof(value_);
-        } else {
-            return nullptr;
-        }
-    }
-    constexpr T*       end() noexcept { return begin() + has_value(); }
-    constexpr const T* end() const noexcept { return begin() + has_value(); }
-
-    constexpr std::reverse_iterator<T*>       rbegin() noexcept { return reverse_iterator(end()); }
-    constexpr std::reverse_iterator<const T*> rbegin() const noexcept { return reverse_iterator(end()); }
-    constexpr std::reverse_iterator<T*>       rend() noexcept { return reverse_iterator(begin()); }
-    constexpr std::reverse_iterator<const T*> rend() const noexcept { return reverse_iterator(begin()); }
-
-    constexpr const T*                        cbegin() const noexcept { return begin(); }
-    constexpr const T*                        cend() const noexcept { return end(); }
-    constexpr std::reverse_iterator<const T*> crbegin() const noexcept { return rbegin(); }
-    constexpr std::reverse_iterator<const T*> crend() const noexcept { return rend(); }
 };
 
 template <typename T, typename U>
@@ -947,6 +932,12 @@ template <class T>
 class optional<T&> {
   public:
     using value_type = T&;
+    // Since ${PAPER_NUMBER}: ${PAPER_TITLE}.
+    // Note: P3168 and P2988 may have different flows inside LEWG/LWG.
+    // Implementation of the range support for optional<T&> reflects P3168R1 for now.
+    // [optional.iterators], iterator support
+    using iterator       = T*;       // see [optional.iterators]
+    using const_iterator = const T*; // see [optional.iterators]
 
     // [optional.ctor], constructors
     //    constexpr optional() noexcept;
@@ -1076,6 +1067,15 @@ class optional<T&> {
 
     constexpr void swap(optional& rhs) noexcept { std::swap(value_, rhs.value_); }
 
+    // Since ${PAPER_NUMBER}: ${PAPER_TITLE}.
+    // Note: P3168 and P2988 may have different flows inside LEWG/LWG.
+    // Implementation of the range support for optional<T&> reflects P3168R1 for now.
+    // [optional.iterators], iterator support
+    constexpr iterator       begin() noexcept { return has_value() ? value_ : nullptr; };
+    constexpr const_iterator begin() const noexcept { return has_value() ? value_ : nullptr; };
+    constexpr iterator       end() noexcept { return begin() + has_value(); }
+    constexpr const_iterator end() const noexcept { return begin() + has_value(); }
+
     // \rSec3[optional.observe]{Observers}
     constexpr T* operator->() const noexcept { return value_; }
 
@@ -1120,37 +1120,7 @@ class optional<T&> {
     }
 
     constexpr void reset() noexcept { value_ = nullptr; }
-    using iterator       = T*;
-    using const_iterator = const T*;
-
-    // [optional.iterators], iterator support
-    constexpr T* begin() noexcept {
-        if (has_value()) {
-            return value_;
-        } else {
-            return nullptr;
-        }
-    }
-    constexpr const T* begin() const noexcept {
-        if (has_value()) {
-            return value_;
-        } else {
-            return nullptr;
-        }
-    }
-    constexpr T* end() noexcept { return begin() + has_value(); }
-
-    constexpr const T* end() const noexcept { return begin() + has_value(); }
-
-    constexpr std::reverse_iterator<T*>       rbegin() noexcept { return reverse_iterator(end()); }
-    constexpr std::reverse_iterator<const T*> rbegin() const noexcept { return reverse_iterator(end()); }
-    constexpr std::reverse_iterator<T*>       rend() noexcept { return reverse_iterator(begin()); }
-    constexpr std::reverse_iterator<const T*> rend() const noexcept { return reverse_iterator(begin()); }
-
-    constexpr const T*                        cbegin() const noexcept { return begin(); }
-    constexpr const T*                        cend() const noexcept { return end(); }
-    constexpr std::reverse_iterator<const T*> crbegin() const noexcept { return rbegin(); }
-    constexpr std::reverse_iterator<const T*> crend() const noexcept { return rend(); }
 };
 } // namespace beman::optional
-#endif
+
+#endif // BEMAN_OPTIONAL26_OPTIONAL_HPP
diff --git a/src/Beman/CMakeLists.txt b/src/Beman/CMakeLists.txt
@@ -1 +1 @@
-add_subdirectory(optional)
+add_subdirectory(Optional26)
diff --git a/src/Beman/optional/CMakeLists.txt → src/Beman/Optional26/CMakeLists.txt b/src/Beman/optional/CMakeLists.txt → src/Beman/Optional26/CMakeLists.txt
@@ -37,10 +37,11 @@ add_executable(optional_test "")
 target_sources(
   optional_test
   PRIVATE
-  optional.t.cpp
-  optional_ref.t.cpp
-  optional_monadic.t.cpp
-  optional_ref_monadic.t.cpp
+  tests/optional.t.cpp
+  tests/optional_ref.t.cpp
+  tests/optional_monadic.t.cpp
+  tests/optional_range_support.t.cpp
+  tests/optional_ref_monadic.t.cpp
 )
 
 target_link_libraries(optional_test "${TARGET_LIBRARY}")

diff --git a/src/Beman/optional/optional.cpp → src/Beman/Optional26/optional.cpp b/src/Beman/optional/optional.cpp → src/Beman/Optional26/optional.cpp
diff --git a/src/Beman/optional/optional.t.cpp → src/Beman/Optional26/tests/optional.t.cpp b/src/Beman/optional/optional.t.cpp → src/Beman/Optional26/tests/optional.t.cpp
@@ -638,42 +638,6 @@ TEST(ViewMaybeTest, Constructors) {
     beman::optional::optional<std::optional<int>> n3{std::optional<int>{}};
 }
 
-TEST(ViewMaybeTest, ConceptCheck) {
-    static_assert(std::ranges::range<beman::optional::optional<int>>);
-    static_assert(std::ranges::view<beman::optional::optional<int>>);
-    static_assert(std::ranges::input_range<beman::optional::optional<int>>);
-    static_assert(std::ranges::forward_range<beman::optional::optional<int>>);
-    static_assert(std::ranges::bidirectional_range<beman::optional::optional<int>>);
-    static_assert(std::ranges::contiguous_range<beman::optional::optional<int>>);
-    static_assert(std::ranges::common_range<beman::optional::optional<int>>);
-    static_assert(std::ranges::viewable_range<beman::optional::optional<int>>);
-    static_assert(!std::ranges::borrowed_range<beman::optional::optional<int>>);
-    static_assert(std::ranges::random_access_range<beman::optional::optional<int>>);
-    static_assert(std::ranges::sized_range<beman::optional::optional<int>>);
-
-    static_assert(std::ranges::range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::view<beman::optional::optional<int*>>);
-    static_assert(std::ranges::input_range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::forward_range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::bidirectional_range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::contiguous_range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::common_range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::viewable_range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::borrowed_range<beman::optional::optional<int*>>);
-    static_assert(std::ranges::random_access_range<beman::optional::optional<int*>>);
-
-    using ref = std::reference_wrapper<int>;
-    static_assert(std::ranges::range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::view<beman::optional::optional<ref>>);
-    static_assert(std::ranges::input_range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::forward_range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::bidirectional_range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::contiguous_range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::common_range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::viewable_range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::borrowed_range<beman::optional::optional<ref>>);
-    static_assert(std::ranges::random_access_range<beman::optional::optional<ref>>);
-}
 
 TEST(ViewMaybeTest, ConceptCheckRef) {
     static_assert(std::ranges::range<beman::optional::optional<int&>>);
@@ -823,8 +787,8 @@ TEST(ViewMaybe, CompTestRef) {
 // (This uses one syntax for constrained lambdas
 // in C++20.)
 inline constexpr auto and_then = [](auto&& r, auto fun) {
-    return decltype(r)(r) | std::ranges::views::transform(std::move(fun)) |
-           std::ranges::views::join;
+    return decltype(r)(r) | std::views::transform(std::move(fun)) |
+           std::views::join;
 };
 
 // "yield_if" takes a bool and a value and
@@ -837,7 +801,7 @@ inline constexpr auto yield_if = []<class T>(bool b, T x) {
 
 
 TEST(ViewMaybeTest, PythTripleTest) {
-    using std::ranges::views::iota;
+    using std::views::iota;
     auto triples = and_then(iota(1), [](int z) {
         return and_then(iota(1, z + 1), [=](int x) {
             return and_then(iota(x, z + 1), [=](int y) {

diff --git a/src/Beman/optional/optional_monadic.t.cpp → ...n/Optional26/tests/optional_monadic.t.cpp b/src/Beman/optional/optional_monadic.t.cpp → ...n/Optional26/tests/optional_monadic.t.cpp
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		add_subdirectory(optional)
		add_subdirectory(Optional26)