diff --git a/.github/workflows/bvt-appleclang.yml b/.github/workflows/bvt-appleclang.yml
index cc1f0504..7e9d8381 100644
--- a/.github/workflows/bvt-appleclang.yml
+++ b/.github/workflows/bvt-appleclang.yml
@@ -20,7 +20,7 @@ jobs:
 
     - name: build and run test with AppleClang
       run: |
-        cmake -B build -DCMAKE_BUILD_TYPE=Release
+        cmake -B build -DCMAKE_CXX_STANDARD=23 -DCMAKE_BUILD_TYPE=Release
         cmake --build build -j
         ctest --test-dir build -j
 
diff --git a/.github/workflows/bvt-clang.yml b/.github/workflows/bvt-clang.yml
index c58b1004..d8d765d4 100644
--- a/.github/workflows/bvt-clang.yml
+++ b/.github/workflows/bvt-clang.yml
@@ -15,39 +15,25 @@ jobs:
 
     - name: install clang
       run: |
-        sudo apt install -y clang-16 clang-17 clang-18 libc++-18-dev
+        sudo apt install -y clang-19 libc++-19-dev
 
-    - name: check compiler versions
+    - name: check compiler version
       run: |
-        clang++-16 --version
-        clang++-17 --version
-        clang++-18 --version
+        clang++-19 --version
 
-    - name: build and run test with clang 16
+    - name: build and run test with clang 19
       run: |
-        cmake -B build-clang-16 -DCMAKE_C_COMPILER=clang-16 -DCMAKE_CXX_COMPILER=clang++-16 -DCMAKE_CXX_FLAGS="-stdlib=libc++" -DCMAKE_BUILD_TYPE=Release
-        cmake --build build-clang-16 -j
-        ctest --test-dir build-clang-16 -j
-
-    - name: build and run test with clang 17
-      run: |
-        cmake -B build-clang-17 -DCMAKE_C_COMPILER=clang-17 -DCMAKE_CXX_COMPILER=clang++-17 -DCMAKE_CXX_FLAGS="-stdlib=libc++" -DCMAKE_BUILD_TYPE=Release
-        cmake --build build-clang-17 -j
-        ctest --test-dir build-clang-17 -j
-
-    - name: build and run test with clang 18
-      run: |
-        cmake -B build-clang-18 -DCMAKE_C_COMPILER=clang-18 -DCMAKE_CXX_COMPILER=clang++-18 -DCMAKE_CXX_FLAGS="-stdlib=libc++" -DCMAKE_BUILD_TYPE=Release
-        cmake --build build-clang-18 -j
-        ctest --test-dir build-clang-18 -j
+        cmake -B build -DCMAKE_C_COMPILER=clang-19 -DCMAKE_CXX_COMPILER=clang++-19 -DCMAKE_CXX_FLAGS="-stdlib=libc++" -DCMAKE_CXX_STANDARD=23 -DCMAKE_BUILD_TYPE=Release
+        cmake --build build -j
+        ctest --test-dir build -j
 
     - name: run benchmarks
       run: |
-        cd build-clang-18/benchmarks
+        cd build/benchmarks
         ./msft_proxy_benchmarks --benchmark_min_warmup_time=0.1 --benchmark_min_time=0.1s --benchmark_repetitions=30 --benchmark_enable_random_interleaving=true --benchmark_report_aggregates_only=true --benchmark_format=json > benchmarking-results.json
 
     - name: archive benchmarking results
       uses: actions/upload-artifact@v4
       with:
         name: benchmarking-results-clang
-        path: build-clang-18/benchmarks/benchmarking-results.json
+        path: build/benchmarks/benchmarking-results.json
diff --git a/.github/workflows/bvt-compatibility.yml b/.github/workflows/bvt-compatibility.yml
new file mode 100644
index 00000000..4169e634
--- /dev/null
+++ b/.github/workflows/bvt-compatibility.yml
@@ -0,0 +1,64 @@
+on:
+  workflow_call:
+    inputs:
+      branch:
+        type: string
+        required: false
+
+jobs:
+  bvt-compatibility:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        ref: ${{ inputs.branch }}
+
+    - name: install compilers
+      run: |
+        sudo apt install -y gcc-13 g++-13 gcc-14 g++-14 clang-16 clang-17 clang-18 clang-19 libc++-19-dev
+
+    - name: check compiler versions
+      run: |
+        g++-13 --version
+        g++-14 --version
+        clang++-16 --version
+        clang++-17 --version
+        clang++-18 --version
+        clang++-19 --version
+
+    - name: build and run test with gcc 13
+      run: |
+        cmake -B build-gcc-13 -DCMAKE_C_COMPILER=gcc-13 -DCMAKE_CXX_COMPILER=g++-13 -DCMAKE_BUILD_TYPE=Release
+        cmake --build build-gcc-13 -j
+        ctest --test-dir build-gcc-13 -j
+
+    - name: build and run test with gcc 14
+      run: |
+        cmake -B build-gcc-14 -DCMAKE_C_COMPILER=gcc-14 -DCMAKE_CXX_COMPILER=g++-14 -DCMAKE_BUILD_TYPE=Release
+        cmake --build build-gcc-14 -j
+        ctest --test-dir build-gcc-14 -j
+
+    # Note that libc++ in Clang 19 is not compatible with Clang 16. Therefore, we fallback to libstdc++.
+    - name: build and run test with clang 16
+      run: |
+        cmake -B build-clang-16 -DCMAKE_C_COMPILER=clang-16 -DCMAKE_CXX_COMPILER=clang++-16 -DCMAKE_BUILD_TYPE=Release
+        cmake --build build-clang-16 -j
+        ctest --test-dir build-clang-16 -j
+
+    - name: build and run test with clang 17
+      run: |
+        cmake -B build-clang-17 -DCMAKE_C_COMPILER=clang-17 -DCMAKE_CXX_COMPILER=clang++-17 -DCMAKE_CXX_FLAGS="-stdlib=libc++" -DCMAKE_BUILD_TYPE=Release
+        cmake --build build-clang-17 -j
+        ctest --test-dir build-clang-17 -j
+
+    - name: build and run test with clang 18
+      run: |
+        cmake -B build-clang-18 -DCMAKE_C_COMPILER=clang-18 -DCMAKE_CXX_COMPILER=clang++-18 -DCMAKE_CXX_FLAGS="-stdlib=libc++" -DCMAKE_BUILD_TYPE=Release
+        cmake --build build-clang-18 -j
+        ctest --test-dir build-clang-18 -j
+
+    - name: build and run test with clang 19
+      run: |
+        cmake -B build-clang-19 -DCMAKE_C_COMPILER=clang-19 -DCMAKE_CXX_COMPILER=clang++-19 -DCMAKE_CXX_FLAGS="-stdlib=libc++" -DCMAKE_BUILD_TYPE=Release
+        cmake --build build-clang-19 -j
+        ctest --test-dir build-clang-19 -j
diff --git a/.github/workflows/bvt-gcc.yml b/.github/workflows/bvt-gcc.yml
index ea33f230..e3a86037 100644
--- a/.github/workflows/bvt-gcc.yml
+++ b/.github/workflows/bvt-gcc.yml
@@ -15,32 +15,25 @@ jobs:
 
     - name: install gcc
       run: |
-        sudo apt install -y gcc-13 g++-13 gcc-14 g++-14
+        sudo apt install -y gcc-14 g++-14
 
-    - name: check compiler versions
+    - name: check compiler version
       run: |
-        g++-13 --version
         g++-14 --version
 
-    - name: build and run test with gcc 13
-      run: |
-        cmake -B build-gcc-13 -DCMAKE_C_COMPILER=gcc-13 -DCMAKE_CXX_COMPILER=g++-13 -DCMAKE_BUILD_TYPE=Release
-        cmake --build build-gcc-13 -j
-        ctest --test-dir build-gcc-13 -j
-
     - name: build and run test with gcc 14
       run: |
-        cmake -B build-gcc-14 -DCMAKE_C_COMPILER=gcc-14 -DCMAKE_CXX_COMPILER=g++-14 -DCMAKE_BUILD_TYPE=Release
-        cmake --build build-gcc-14 -j
-        ctest --test-dir build-gcc-14 -j
+        cmake -B build -DCMAKE_C_COMPILER=gcc-14 -DCMAKE_CXX_COMPILER=g++-14 -DCMAKE_CXX_STANDARD=23 -DCMAKE_BUILD_TYPE=Release
+        cmake --build build -j
+        ctest --test-dir build -j
 
     - name: run benchmarks
       run: |
-        cd build-gcc-14/benchmarks
+        cd build/benchmarks
         ./msft_proxy_benchmarks --benchmark_min_warmup_time=0.1 --benchmark_min_time=0.1s --benchmark_repetitions=30 --benchmark_enable_random_interleaving=true --benchmark_report_aggregates_only=true --benchmark_format=json > benchmarking-results.json
 
     - name: archive benchmarking results
       uses: actions/upload-artifact@v4
       with:
         name: benchmarking-results-gcc
-        path: build-gcc-14/benchmarks/benchmarking-results.json
+        path: build/benchmarks/benchmarking-results.json
diff --git a/.github/workflows/bvt-msvc.yml b/.github/workflows/bvt-msvc.yml
index 0f5aecbb..eff391be 100644
--- a/.github/workflows/bvt-msvc.yml
+++ b/.github/workflows/bvt-msvc.yml
@@ -7,7 +7,7 @@ on:
 
 jobs:
   bvt-msvc:
-    runs-on: windows-2022
+    runs-on: windows-2025
     steps:
     - uses: actions/checkout@v4
       with:
@@ -15,7 +15,7 @@ jobs:
 
     - name: build and run test with MSVC
       run: |
-        cmake -B build
+        cmake -B build -DCMAKE_CXX_STANDARD=23
         cmake --build build --config Release -j
         ctest --test-dir build -j
 
diff --git a/.github/workflows/bvt-nvhpc.yml b/.github/workflows/bvt-nvhpc.yml
index 4dcc808e..273428f7 100644
--- a/.github/workflows/bvt-nvhpc.yml
+++ b/.github/workflows/bvt-nvhpc.yml
@@ -23,17 +23,17 @@ jobs:
     - name: build and run test with NVHPC 24.9
       run: |
         PATH=/opt/nvidia/hpc_sdk/Linux_x86_64/24.9/compilers/bin:$PATH; export PATH
-        cmake -B build-nv -DCMAKE_C_COMPILER=nvc -DCMAKE_CXX_COMPILER=nvc++ -DCMAKE_BUILD_TYPE=Release
-        cmake --build build-nv -j
-        ctest --test-dir build-nv -j
+        cmake -B build -DCMAKE_C_COMPILER=nvc -DCMAKE_CXX_COMPILER=nvc++ -DCMAKE_BUILD_TYPE=Release
+        cmake --build build -j
+        ctest --test-dir build -j
 
     - name: run benchmarks
       run: |
-        cd build-nv/benchmarks
+        cd build/benchmarks
         ./msft_proxy_benchmarks --benchmark_min_warmup_time=0.1 --benchmark_min_time=0.1s --benchmark_repetitions=30 --benchmark_enable_random_interleaving=true --benchmark_report_aggregates_only=true --benchmark_format=json > benchmarking-results.json
 
     - name: archive benchmarking results
       uses: actions/upload-artifact@v4
       with:
         name: benchmarking-results-nvhpc
-        path: build-nv/benchmarks/benchmarking-results.json
+        path: build/benchmarks/benchmarking-results.json
diff --git a/.github/workflows/pipeline-ci.yml b/.github/workflows/pipeline-ci.yml
index 9cc56653..28b0dcbd 100644
--- a/.github/workflows/pipeline-ci.yml
+++ b/.github/workflows/pipeline-ci.yml
@@ -28,6 +28,10 @@ jobs:
     uses: ./.github/workflows/bvt-nvhpc.yml
     name: Run BVT with NVHPC
 
+  run-bvt-compatibility:
+    uses: ./.github/workflows/bvt-compatibility.yml
+    name: Run BVT for compatibility
+
   report:
     uses: ./.github/workflows/bvt-report.yml
     name: Generate report
diff --git a/benchmarks/CMakeLists.txt b/benchmarks/CMakeLists.txt
index 3b500d1f..393f5cd9 100644
--- a/benchmarks/CMakeLists.txt
+++ b/benchmarks/CMakeLists.txt
@@ -26,6 +26,8 @@ target_link_libraries(msft_proxy_benchmarks PRIVATE msft_proxy benchmark::benchm
 
 if (MSVC)
   target_compile_options(msft_proxy_benchmarks PRIVATE /W4)
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+  target_compile_options(msft_proxy_benchmarks PRIVATE -Wall -Wextra -Wpedantic -Wno-c++2b-extensions)
 else()
   target_compile_options(msft_proxy_benchmarks PRIVATE -Wall -Wextra -Wpedantic)
 endif()
diff --git a/proxy.h b/proxy.h
index 74877c92..3a6882f2 100644
--- a/proxy.h
+++ b/proxy.h
@@ -22,10 +22,10 @@
 #include <format>
 #endif  // __STDC_HOSTED__
 
-#ifdef __cpp_rtti
+#if __cpp_rtti >= 199711L
 #include <optional>
 #include <typeinfo>
-#endif  // __cpp_rtti
+#endif  // __cpp_rtti >= 199711L
 
 #if __has_cpp_attribute(msvc::no_unique_address)
 #define ___PRO_NO_UNIQUE_ADDRESS_ATTRIBUTE msvc::no_unique_address
@@ -35,11 +35,11 @@
 #error "Proxy requires C++20 attribute no_unique_address"
 #endif
 
-#ifdef __cpp_exceptions
+#if __cpp_exceptions >= 199711L
 #define ___PRO_THROW(...) throw __VA_ARGS__
 #else
 #define ___PRO_THROW(...) std::abort()
-#endif  // __cpp_exceptions
+#endif  // __cpp_exceptions >= 199711L
 
 #ifdef _MSC_VER
 #define ___PRO_ENFORCE_EBO __declspec(empty_bases)
@@ -1576,12 +1576,18 @@ constexpr proxy<F> make_proxy_shared(T&& value)
 }
 #endif  // __STDC_HOSTED__
 
-#ifdef __cpp_rtti
+#if __cpp_rtti >= 199711L
 class bad_proxy_cast : public std::bad_cast {
  public:
   char const* what() const noexcept override { return "pro::bad_proxy_cast"; }
 };
-#endif  // __cpp_rtti
+#endif  // __cpp_rtti >= 199711L
+
+#if __cpp_static_call_operator >= 202207L
+#define ___PRO_STATIC_CALL(__R, ...) static __R operator()(__VA_ARGS__)
+#else
+#define ___PRO_STATIC_CALL(__R, ...) __R operator()(__VA_ARGS__) const
+#endif  // __cpp_static_call_operator >= 202207L
 
 #define ___PRO_DIRECT_FUNC_IMPL(...) \
     noexcept(noexcept(__VA_ARGS__)) requires(requires { __VA_ARGS__; }) \
@@ -1672,7 +1678,7 @@ class bad_proxy_cast : public std::bad_cast {
 #define ___PRO_DEF_MEM_DISPATCH_IMPL(__NAME, __FUNC, __FNAME) \
     struct __NAME { \
       template <class __T, class... __Args> \
-      decltype(auto) operator()(__T&& __self, __Args&&... __args) const \
+      ___PRO_STATIC_CALL(decltype(auto), __T&& __self, __Args&&... __args) \
           ___PRO_DIRECT_FUNC_IMPL(::std::forward<__T>(__self) \
               .__FUNC(::std::forward<__Args>(__args)...)) \
       ___PRO_DEF_MEM_ACCESSOR_TEMPLATE(___PRO_DEF_MEM_ACCESSOR, __FNAME) \
@@ -1705,7 +1711,7 @@ ___PRO_DEBUG( \
 #define ___PRO_DEF_FREE_DISPATCH_IMPL(__NAME, __FUNC, __FNAME) \
     struct __NAME { \
       template <class __T, class... __Args> \
-      decltype(auto) operator()(__T&& __self, __Args&&... __args) const \
+      ___PRO_STATIC_CALL(decltype(auto), __T&& __self, __Args&&... __args) \
           ___PRO_DIRECT_FUNC_IMPL(__FUNC(::std::forward<__T>(__self), \
               ::std::forward<__Args>(__args)...)) \
       ___PRO_DEF_FREE_ACCESSOR_TEMPLATE(___PRO_DEF_FREE_ACCESSOR, __FNAME) \
@@ -1720,7 +1726,7 @@ ___PRO_DEBUG( \
 #define ___PRO_DEF_FREE_AS_MEM_DISPATCH_IMPL(__NAME, __FUNC, __FNAME) \
     struct __NAME { \
       template <class __T, class... __Args> \
-      decltype(auto) operator()(__T&& __self, __Args&&... __args) const \
+      ___PRO_STATIC_CALL(decltype(auto), __T&& __self, __Args&&... __args) \
           ___PRO_DIRECT_FUNC_IMPL(__FUNC(::std::forward<__T>(__self), \
               ::std::forward<__Args>(__args)...)) \
       ___PRO_DEF_MEM_ACCESSOR_TEMPLATE(___PRO_DEF_MEM_ACCESSOR, __FNAME) \
@@ -1758,7 +1764,7 @@ struct cast_dispatch_base {
 
 struct upward_conversion_dispatch : cast_dispatch_base<false, true> {
   template <class T>
-  T&& operator()(T&& self) const noexcept { return std::forward<T>(self); }
+  ___PRO_STATIC_CALL(T&&, T&& self) noexcept { return std::forward<T>(self); }
 };
 
 template <class T>
@@ -1932,7 +1938,7 @@ using merge_facade_conv_t = typename add_upward_conversion_conv<
 
 struct proxy_view_dispatch : cast_dispatch_base<false, true> {
   template <class T>
-  auto operator()(T& value) const noexcept
+  ___PRO_STATIC_CALL(auto, T& value) noexcept
       requires(requires { { std::addressof(*value) } noexcept; }) {
     return observer_ptr<decltype(*value), decltype(*std::as_const(value)),
         decltype(*std::move(value)), decltype(*std::move(std::as_const(value)))>
@@ -2026,7 +2032,7 @@ sign(const char (&str)[N]) -> sign<N>;
 #if __STDC_HOSTED__
 struct weak_conversion_dispatch : cast_dispatch_base<false, true> {
   template <class P>
-  auto operator()(const P& self) const noexcept
+  ___PRO_STATIC_CALL(auto, const P& self) noexcept
       requires(requires { typename P::weak_type; } &&
           std::is_convertible_v<const P&, typename P::weak_type>)
       { return typename P::weak_type{self}; }
@@ -2078,14 +2084,14 @@ struct format_dispatch {
   // std::formatter by std::is_default_constructible_v as per
   // [format.formatter.spec].
   template <class T, class CharT, class OutIt>
-  OutIt operator()(const T& self, std::basic_string_view<CharT> spec,
-      std::basic_format_context<OutIt, CharT>& fc) const
+  ___PRO_STATIC_CALL(OutIt, const T& self, std::basic_string_view<CharT> spec,
+      std::basic_format_context<OutIt, CharT>& fc)
       requires(
-#if defined(__cpp_lib_format_ranges) && __cpp_lib_format_ranges >= 202207L
+#if __cpp_lib_format_ranges >= 202207L
           std::formattable<T, CharT>
 #else
           std::is_default_constructible_v<std::formatter<T, CharT>>
-#endif  // defined(__cpp_lib_format_ranges) && __cpp_lib_format_ranges >= 202207L
+#endif  // __cpp_lib_format_ranges >= 202207L
       ) {
     std::formatter<T, CharT> impl;
     {
@@ -2097,7 +2103,7 @@ struct format_dispatch {
 };
 #endif  // __STDC_HOSTED__
 
-#ifdef __cpp_rtti
+#if __cpp_rtti >= 199711L
 struct proxy_cast_context {
   const std::type_info* type_ptr;
   bool is_ref;
@@ -2152,7 +2158,7 @@ struct proxy_cast_accessor_impl {
               void(proxy_cast_context) Q> {}
 struct proxy_cast_dispatch {
   template <class T>
-  void operator()(T&& self, proxy_cast_context ctx) const {
+  ___PRO_STATIC_CALL(void, T&& self, proxy_cast_context ctx) {
     if (typeid(T) == *ctx.type_ptr) {
       if (ctx.is_ref) {
         if constexpr (std::is_lvalue_reference_v<T>) {
@@ -2199,18 +2205,18 @@ ___PRO_DEBUG(
 
   const std::type_info* info;
 };
-#endif  // __cpp_rtti
+#endif  // __cpp_rtti >= 199711L
 
 struct wildcard {
   wildcard() = delete;
 
   template <class T>
   [[noreturn]] operator T() const {
-#ifdef __cpp_lib_unreachable
+#if __cpp_lib_unreachable >= 202202L
     std::unreachable();
 #else
     std::abort();
-#endif  // __cpp_lib_unreachable
+#endif  // __cpp_lib_unreachable >= 202202L
   }
 };
 
@@ -2264,7 +2270,7 @@ struct basic_facade_builder {
   using support_wformat = add_convention<
       details::format_dispatch, details::format_overload_t<wchar_t>>;
 #endif  // __STDC_HOSTED__
-#ifdef __cpp_rtti
+#if __cpp_rtti >= 199711L
   using support_indirect_rtti = basic_facade_builder<
       details::add_conv_t<Cs, details::conv_impl<false,
           details::proxy_cast_dispatch, void(details::proxy_cast_context) &,
@@ -2280,7 +2286,7 @@ struct basic_facade_builder {
       details::add_tuple_t<Rs, details::refl_impl<true,
           details::proxy_typeid_reflector>>, C>;
   using support_rtti = support_indirect_rtti;
-#endif  // __cpp_rtti
+#endif  // __cpp_rtti >= 199711L
   using support_view = add_direct_convention<details::proxy_view_dispatch,
       facade_aware_overload_t<details::proxy_view_overload>>;
   using build = details::facade_impl<Cs, Rs, details::normalize(C)>;
@@ -2340,18 +2346,18 @@ struct operator_dispatch;
 #define ___PRO_DEF_LHS_ALL_OP_ACCESSOR ___PRO_DEF_LHS_ANY_OP_ACCESSOR
 #define ___PRO_LHS_LEFT_OP_DISPATCH_BODY_IMPL(...) \
     template <class T> \
-    decltype(auto) operator()(T&& self) const \
+    ___PRO_STATIC_CALL(decltype(auto), T&& self) \
         ___PRO_DIRECT_FUNC_IMPL(__VA_ARGS__ std::forward<T>(self))
 #define ___PRO_LHS_UNARY_OP_DISPATCH_BODY_IMPL(...) \
     template <class T> \
-    decltype(auto) operator()(T&& self) const \
+    ___PRO_STATIC_CALL(decltype(auto), T&& self) \
         ___PRO_DIRECT_FUNC_IMPL(__VA_ARGS__ std::forward<T>(self)) \
     template <class T> \
-    decltype(auto) operator()(T&& self, int) const \
+    ___PRO_STATIC_CALL(decltype(auto), T&& self, int) \
         ___PRO_DIRECT_FUNC_IMPL(std::forward<T>(self) __VA_ARGS__)
 #define ___PRO_LHS_BINARY_OP_DISPATCH_BODY_IMPL(...) \
     template <class T, class Arg> \
-    decltype(auto) operator()(T&& self, Arg&& arg) const \
+    ___PRO_STATIC_CALL(decltype(auto), T&& self, Arg&& arg) \
         ___PRO_DIRECT_FUNC_IMPL( \
             std::forward<T>(self) __VA_ARGS__ std::forward<Arg>(arg))
 #define ___PRO_LHS_ALL_OP_DISPATCH_BODY_IMPL(...) \
@@ -2386,7 +2392,7 @@ ___PRO_DEBUG( \
     template <> \
     struct operator_dispatch<#__VA_ARGS__, true> { \
       template <class T, class Arg> \
-      decltype(auto) operator()(T&& self, Arg&& arg) const \
+      ___PRO_STATIC_CALL(decltype(auto), T&& self, Arg&& arg) \
           ___PRO_DIRECT_FUNC_IMPL( \
               std::forward<Arg>(arg) __VA_ARGS__ std::forward<T>(self)) \
       ___PRO_DEF_FREE_ACCESSOR_TEMPLATE( \
@@ -2433,7 +2439,7 @@ ___PRO_DEBUG( \
     template <> \
     struct operator_dispatch<#__VA_ARGS__, false> { \
       template <class T, class Arg> \
-      decltype(auto) operator()(T&& self, Arg&& arg) const \
+      ___PRO_STATIC_CALL(decltype(auto), T&& self, Arg&& arg) \
           ___PRO_DIRECT_FUNC_IMPL(std::forward<T>(self) __VA_ARGS__ \
               std::forward<Arg>(arg)) \
       ___PRO_DEF_MEM_ACCESSOR_TEMPLATE(___PRO_DEF_LHS_ASSIGNMENT_OP_ACCESSOR, \
@@ -2442,7 +2448,7 @@ ___PRO_DEBUG( \
     template <> \
     struct operator_dispatch<#__VA_ARGS__, true> { \
       template <class T, class Arg> \
-      decltype(auto) operator()(T&& self, Arg&& arg) const \
+      ___PRO_STATIC_CALL(decltype(auto), T&& self, Arg&& arg) \
           ___PRO_DIRECT_FUNC_IMPL( \
               std::forward<Arg>(arg) __VA_ARGS__ std::forward<T>(self)) \
       ___PRO_DEF_FREE_ACCESSOR_TEMPLATE(___PRO_DEF_RHS_ASSIGNMENT_OP_ACCESSOR, \
@@ -2487,23 +2493,23 @@ ___PRO_BINARY_OP_DISPATCH_IMPL(->*)
 template <>
 struct operator_dispatch<"()", false> {
   template <class T, class... Args>
-  decltype(auto) operator()(T&& self, Args&&... args) const
+  ___PRO_STATIC_CALL(decltype(auto), T&& self, Args&&... args)
       ___PRO_DIRECT_FUNC_IMPL(
           std::forward<T>(self)(std::forward<Args>(args)...))
   ___PRO_DEF_MEM_ACCESSOR_TEMPLATE(___PRO_DEF_LHS_ANY_OP_ACCESSOR, operator())
 };
 template <>
 struct operator_dispatch<"[]", false> {
-#if defined(__cpp_multidimensional_subscript) && __cpp_multidimensional_subscript >= 202110L
+#if __cpp_multidimensional_subscript >= 202110L
   template <class T, class... Args>
-  decltype(auto) operator()(T&& self, Args&&... args) const
+  ___PRO_STATIC_CALL(decltype(auto), T&& self, Args&&... args)
       ___PRO_DIRECT_FUNC_IMPL(
           std::forward<T>(self)[std::forward<Args>(args)...])
 #else
   template <class T, class Arg>
-  decltype(auto) operator()(T&& self, Arg&& arg) const
+  ___PRO_STATIC_CALL(decltype(auto), T&& self, Arg&& arg)
       ___PRO_DIRECT_FUNC_IMPL(std::forward<T>(self)[std::forward<Arg>(arg)])
-#endif  // defined(__cpp_multidimensional_subscript) && __cpp_multidimensional_subscript >= 202110L
+#endif  // __cpp_multidimensional_subscript >= 202110L
   ___PRO_DEF_MEM_ACCESSOR_TEMPLATE(___PRO_DEF_LHS_ANY_OP_ACCESSOR, operator[])
 };
 
@@ -2528,11 +2534,11 @@ struct operator_dispatch<"[]", false> {
 struct implicit_conversion_dispatch
     : details::cast_dispatch_base<false, false> {
   template <class T>
-  T&& operator()(T&& self) const noexcept { return std::forward<T>(self); }
+  ___PRO_STATIC_CALL(T&&, T&& self) noexcept { return std::forward<T>(self); }
 };
 struct explicit_conversion_dispatch : details::cast_dispatch_base<true, false> {
   template <class T>
-  auto operator()(T&& self) const noexcept
+  ___PRO_STATIC_CALL(auto, T&& self) noexcept
       { return details::explicit_conversion_adapter<T>{std::forward<T>(self)}; }
 };
 using conversion_dispatch = explicit_conversion_dispatch;
@@ -2546,7 +2552,7 @@ template <class D>
 struct weak_dispatch : D {
   using D::operator();
   template <class... Args>
-  [[noreturn]] details::wildcard operator()(std::nullptr_t, Args&&...) const
+  [[noreturn]] ___PRO_STATIC_CALL(details::wildcard, std::nullptr_t, Args&&...)
       { ___PRO_THROW(not_implemented{}); }
 };
 
@@ -2555,7 +2561,7 @@ struct weak_dispatch : D {
         "Use pro::weak_dispatch<" #__D "> instead.")]] __NAME : __D { \
       using __D::operator(); \
       template <class... __Args> \
-      decltype(auto) operator()(::std::nullptr_t, __Args&&... __args) const \
+      ___PRO_STATIC_CALL(decltype(auto), ::std::nullptr_t, __Args&&... __args) \
           ___PRO_DIRECT_FUNC_IMPL(__FUNC(::std::forward<__Args>(__args)...)) \
     }
 
diff --git a/samples/CMakeLists.txt b/samples/CMakeLists.txt
index 46b53b33..29deb3ea 100644
--- a/samples/CMakeLists.txt
+++ b/samples/CMakeLists.txt
@@ -10,10 +10,11 @@ foreach(SOURCE ${SOURCES})
   set(FULL_EXECUTABLE_NAME "${DIR_UNDERSCORE}_${EXECUTABLE_NAME}")
   add_executable(${FULL_EXECUTABLE_NAME} ${SOURCE})
   target_link_libraries(${FULL_EXECUTABLE_NAME} PRIVATE msft_proxy)
+  if (MSVC)
+    target_compile_options(${FULL_EXECUTABLE_NAME} PRIVATE /W4)
+  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    target_compile_options(${FULL_EXECUTABLE_NAME} PRIVATE -Wall -Wextra -Wpedantic -Wno-c++2b-extensions)
+  else()
+    target_compile_options(${FULL_EXECUTABLE_NAME} PRIVATE -Wall -Wextra -Wpedantic)
+  endif()
 endforeach()
-
-if (MSVC)
-  add_compile_options(/W4)
-else()
-  add_compile_options(-Wall -Wextra -Wpedantic)
-endif()
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d5070c9f..020c48b8 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -35,6 +35,8 @@ target_link_libraries(msft_proxy_tests PRIVATE gtest_main)
 
 if(MSVC)
   target_compile_options(msft_proxy_tests PRIVATE /W4 /WX)
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+  target_compile_options(msft_proxy_tests PRIVATE -Wall -Wextra -Wpedantic -Wno-c++2b-extensions -Werror)
 else()
   target_compile_options(msft_proxy_tests PRIVATE -Wall -Wextra -Wpedantic -Werror)
 endif()
@@ -46,7 +48,11 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang
   add_executable(msft_proxy_freestanding_tests freestanding/proxy_freestanding_tests.cpp)
   target_include_directories(msft_proxy_freestanding_tests PRIVATE .)
   target_compile_features(msft_proxy_freestanding_tests PRIVATE cxx_std_20)
-  target_compile_options(msft_proxy_freestanding_tests PRIVATE -ffreestanding -fno-exceptions -fno-rtti -Wall -Wextra -Wpedantic -Werror)
+  if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    target_compile_options(msft_proxy_freestanding_tests PRIVATE -ffreestanding -fno-exceptions -fno-rtti -Wall -Wextra -Wpedantic -Wno-c++2b-extensions -Werror)
+  else()
+    target_compile_options(msft_proxy_freestanding_tests PRIVATE -ffreestanding -fno-exceptions -fno-rtti -Wall -Wextra -Wpedantic -Werror)
+  endif()
   target_link_options(msft_proxy_freestanding_tests PRIVATE -nodefaultlibs -lc)
   target_link_libraries(msft_proxy_freestanding_tests PRIVATE msft_proxy)
   add_test(NAME ProxyFreestandingTests COMMAND msft_proxy_freestanding_tests)
diff --git a/tests/proxy_dispatch_tests.cpp b/tests/proxy_dispatch_tests.cpp
index 090d2a69..aa08a6d0 100644
--- a/tests/proxy_dispatch_tests.cpp
+++ b/tests/proxy_dispatch_tests.cpp
@@ -2,6 +2,7 @@
 // Licensed under the MIT License.
 
 #include <gtest/gtest.h>
+#include <unordered_map>
 #include <vector>
 #if defined(_MSC_VER) && !defined(__clang__)
 #pragma warning(push)
@@ -12,6 +13,10 @@
 #pragma warning(pop)
 #endif  // defined(_MSC_VER) && !defined(__clang__)
 
+#if __cpp_lib_mdspan >= 202207L
+#include <mdspan>
+#endif  // __cpp_lib_mdspan >= 202207L
+
 namespace proxy_dispatch_tests_details {
 
 struct CommaTester {
@@ -333,7 +338,7 @@ TEST(ProxyDispatchTests, TestOpParentheses) {
   ASSERT_EQ((*p)(2, 3), 5);
 }
 
-TEST(ProxyDispatchTests, TestOpBrackets) {
+TEST(ProxyDispatchTests, TestOpBrackets_OneDimensional) {
   struct TestFacade : pro::facade_builder::add_convention<pro::operator_dispatch<"[]">, int&(int idx)>::build {};
   std::unordered_map<int, int> v;
   pro::proxy<TestFacade> p = &v;
@@ -342,6 +347,19 @@ TEST(ProxyDispatchTests, TestOpBrackets) {
   ASSERT_EQ(v.at(3), 12);
 }
 
+#if __cpp_lib_mdspan >= 202207L
+TEST(ProxyDispatchTests, TestOpBrackets_Multidimensional) {
+  struct TestFacade : pro::facade_builder::add_convention<pro::operator_dispatch<"[]">, int&(int i, int j, int k)>::build {};
+  std::vector v(12, 1);
+  auto view = std::mdspan(v.data(), 2, 2, 3);
+  pro::proxy<TestFacade> p = &view;
+  (*p)[1, 1, 1] = 123;
+  for (std::size_t i = 0u; i < v.size(); ++i) {
+    ASSERT_EQ(v[i], i == 10 ? 123 : 1);
+  }
+}
+#endif  // __cpp_lib_mdspan >= 202207L
+
 TEST(ProxyDispatchTests, TestRhsOpPlus) {
   struct TestFacade : pro::facade_builder::add_convention<pro::operator_dispatch<"+", true>, int(int val)>::build {};
   int v = 12;