Drop support for clang 19 with libc++ so that we can support constexp parse function

Author: glynos

.github/workflows/skyr-url-ci.yml

@@ -47,22 +47,6 @@ jobs:
             cxx_standard: 23
           }
 
-          # Clang-18 (C++23)
-          - {
-            name: "Linux Clang 18 Debug (C++23)", artifact: "Linux.tar.xz",
-            os: ubuntu-24.04,
-            build_type: Debug,
-            cc: "clang-18", cxx: "clang++-18",
-            cxx_standard: 23
-          }
-          - {
-            name: "Linux Clang 18 Release (C++23)", artifact: "Linux.tar.xz",
-            os: ubuntu-24.04,
-            build_type: RelWithDebInfo,
-            cc: "clang-18", cxx: "clang++-18",
-            cxx_standard: 23
-          }
-
           # Clang-19 (C++23)
           - {
             name: "Linux Clang 19 Debug (C++23)", artifact: "Linux.tar.xz",
@@ -111,22 +95,6 @@ jobs:
             cxx_standard: 23
           }
 
-          # macOS Clang-18 (C++23)
-          - {
-            name: "macOS Clang 18 Debug (C++23)", artifact: "macOS.tar.xz",
-            os: macos-latest,
-            build_type: Debug,
-            cc: "clang-18", cxx: "clang++-18",
-            cxx_standard: 23
-          }
-          - {
-            name: "macOS Clang 18 Release (C++23)", artifact: "macOS.tar.xz",
-            os: macos-latest,
-            build_type: RelWithDebInfo,
-            cc: "clang-18", cxx: "clang++-18",
-            cxx_standard: 23
-          }
-
           # macOS Clang-19 (C++23)
           - {
             name: "macOS Clang 19 Debug (C++23)", artifact: "macOS.tar.xz",
@@ -255,7 +223,7 @@ jobs:
             COMMAND chmod +x ${cmake_dir}/cmake
           )
 
-      # GCC 13-14 and Clang 18 are pre-installed on ubuntu-24.04
+      # GCC 13-14 are pre-installed on ubuntu-24.04
       # Clang 19-21 need to be installed from LLVM repository
 
       - name: Install Clang and libc++ (C++23 support)
@@ -266,11 +234,9 @@ jobs:
           # Extract version number from compiler name (e.g., clang++-19 -> 19)
           CLANG_VERSION=$(echo "${{ matrix.config.cxx }}" | grep -oP '\d+')
 
-          # Add LLVM repository for newer versions
-          if [[ "$CLANG_VERSION" != "18" ]]; then
-            wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
-            sudo add-apt-repository -y "deb http://apt.llvm.org/noble/ llvm-toolchain-noble-${CLANG_VERSION} main"
-          fi
+          # Add LLVM repository
+          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+          sudo add-apt-repository -y "deb http://apt.llvm.org/noble/ llvm-toolchain-noble-${CLANG_VERSION} main"
 
           sudo apt-get update
 

include/skyr/url_format.hpp

@@ -42,15 +42,6 @@
 /// std::println("{:qd}", url);   // ?name=John Doe (decoded)
 /// \endcode
 
-// Workaround for libc++ versions that don't fully support constexpr in formatter::parse()
-// Some older libc++ implementations (e.g., Homebrew Clang 18 on macOS) have issues
-// with constexpr evaluation in formatter specializations
-#if defined(_LIBCPP_VERSION) && _LIBCPP_VERSION < 190000
-#  define SKYR_FORMAT_PARSE_CONSTEXPR
-#else
-#  define SKYR_FORMAT_PARSE_CONSTEXPR constexpr
-#endif
-
 namespace std {
 template <>
 struct formatter<skyr::url> {
@@ -68,7 +59,7 @@ struct formatter<skyr::url> {
   format_type type_ = format_type::full;
   bool decode_ = false;  // 'd' modifier for decoded output
 
-  SKYR_FORMAT_PARSE_CONSTEXPR auto parse(std::format_parse_context& ctx) -> std::format_parse_context::iterator {
+  constexpr auto parse(std::format_parse_context& ctx) -> std::format_parse_context::iterator {
     auto it = ctx.begin();
     const auto end = ctx.end();
 
@@ -190,6 +181,4 @@ struct formatter<skyr::url> {
 };
 }  // namespace std
 
-#undef SKYR_FORMAT_PARSE_CONSTEXPR
-
 #endif  // SKYR_URL_FORMAT_HPP