Fix compilation with clang-13 and newer.

Drone-CI shows a compilation error with clang-13 and newer.
This patch fixes that compilation error and extends the
Github-CI to detect this.

Author: andreasbuhr

.github/workflows/ubuntu24.yml

@@ -0,0 +1,49 @@
+name: Ubuntu
+
+on:
+  push:
+    branches: [ master, develop ]
+  pull_request:
+    branches: [ master, develop ]
+
+env:
+  # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
+  BUILD_TYPE: Debug
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        compiler_version: [g++-13, g++-14, clang++-20]
+        cxx_std: [20, 23]
+        os: [ubuntu-24.04]
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Clang 20
+        id: install_clang_20
+        if: matrix.compiler_version == 'clang++-20'
+        shell: bash
+        working-directory: ${{ env.HOME }}
+        run: |
+          wget https://apt.llvm.org/llvm.sh
+          chmod +x llvm.sh
+          sudo ./llvm.sh 20
+          sudo apt-get install libc++-20-dev libc++abi-20-dev libunwind-20-dev
+
+      - name: Configure CMake
+        # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
+        # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
+        run: |
+          mkdir build
+          cd build
+          cmake .. -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DCMAKE_CXX_COMPILER=${{ matrix.compiler_version }} -DCXX_STD=${{ matrix.cxx_std }}
+
+      - name: Build
+        run: cd build ; make -j4
+
+      - name: Test
+        run: cd build ; make check

include/boost/parser/search.hpp

@@ -28,10 +28,7 @@ namespace boost::parser {
         template<
             typename R_,
             bool ToCommonRange = false,
-            text::format OtherRangeFormat = no_format,
-            bool = std::is_same_v<sentinel_t<remove_cv_ref_t<R_>>,
-                                  null_sentinel_t> ||
-                   text::detail::is_bounded_array_v<remove_cv_ref_t<R_>>>
+            text::format OtherRangeFormat = no_format>
         struct to_range
         {
             template<typename R>
@@ -75,22 +72,14 @@ namespace boost::parser {
                         return BOOST_PARSER_SUBRANGE(first, last) |
                                as_utf<OtherRangeFormat>;
                     }
+                } else if constexpr (OtherRangeFormat == no_format) {
+                    return (R &&) r;
                 } else {
                     return (R &&) r | as_utf<OtherRangeFormat>;
                 }
             }
         };
 
-        template<typename R_, bool ToCommonRange>
-        struct to_range<R_, ToCommonRange, no_format, false>
-        {
-            template<typename R>
-            static constexpr R && call(R && r)
-            {
-                return (R &&) r;
-            }
-        };
-
         template<typename R>
         using to_range_t = decltype(to_range<R>::call(std::declval<R>()));