Conforming clang19 and libc++

Note that we removed `-Werror` to `-Wno-deprecated-declarations` due to
a bug in clang:llvm/llvm-project#75057

CMakeLists.txt

@@ -24,7 +24,7 @@ set(CXX_FLAGS
     -D_FILE_OFFSET_BITS=64
     -fPIC
     -Wall
-    -Werror
+    -Wno-deprecated-declarations
     -D__STDC_LIMIT_MACROS
     -g
     )

async_simple_module/uthread/Await.cppm

@@ -82,7 +82,7 @@ T await(Future<T>&& fut) {
 export template <class B, class Fn, class C, class... Ts>
 decltype(auto) await(Executor* ex, Fn B::*fn, C* cls, Ts&&... ts) {
     using ValueType =
-        typename std::result_of_t<decltype(fn)(C, Ts && ...)>::ValueType;
+        typename std::invoke_result_t<decltype(fn), C, Ts && ...>::ValueType;
     Promise<ValueType> p;
     auto f = p.getFuture().via(ex);
     auto lazy = [p = std::move(p), fn,
@@ -107,7 +107,7 @@ decltype(auto) await(Executor* ex, Fn B::*fn, C* cls, Ts&&... ts) {
 export template <class Fn, class... Ts>
 decltype(auto) await(Executor* ex, Fn&& fn, Ts&&... ts) {
     using ValueType =
-        typename std::result_of_t<decltype(fn)(Ts && ...)>::ValueType;
+        typename std::invoke_result_t<decltype(fn), Ts && ...>::ValueType;
     Promise<ValueType> p;
     auto f = p.getFuture().via(ex);
     auto lazy = [p = std::move(p),

cmake/FindGTest.cmake

@@ -1,46 +1,18 @@
-if("${GOOGLETEST_ROOT}" STREQUAL "")
-    set(GOOGLETEST_ROOT "/usr/local")
-endif()
-
-if("${GOOGMOCK_ROOT}" STREQUAL "")
-    set(GOOGMOCK_ROOT "/usr/local")
-endif()
-
-find_path(GTEST_INCLUDE_DIR
-    NAMES gtest/gtest.h
-    PATHS ${GOOGLETEST_ROOT}/include)
-
-find_path(GMOCK_INCLUDE_DIR
-    NAMES gmock/gmock.h
-    PATHS ${GOOGMOCK_ROOT}/include)
-
-find_library(GTEST_LIBRARIES
-    NAME gtest
-    PATHS ${GOOGLETEST_ROOT}/lib)
-
-find_library(GMOCK_LIBRARIES
-    NAME gmock
-    PATHS ${GOOGMOCK_ROOT}/lib)
-
-if(NOT GTEST_LIBRARIES OR NOT GMOCK_LIBRARIES)
-  message(STATUS "fetch GTest from https://github.com/google/googletest.git")
-  include(FetchContent)
-  FetchContent_Declare(
-      googletest
-      GIT_REPOSITORY https://github.com/google/googletest.git
-      GIT_TAG release-1.11.0
-  )
-  set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
-  set(BUILD_GMOCK ON CACHE BOOL "" FORCE)
-  set(BUILD_GTEST ON CACHE BOOL "" FORCE)
-  FetchContent_MakeAvailable(googletest)
-  set(GMOCK_INCLUDE_DIR ${CMAKE_BINARY_DIR}/_deps/googletest-src/googlemock/include/)
-  set(GTEST_INCLUDE_DIR ${CMAKE_BINARY_DIR}/_deps/googletest-src/googletest/include/)
-  set(GTEST_LIBRARIES gtest_main)
-  set(GMOCK_LIBRARIES gmock_main)
-else()
-  message(STATUS "use system GTest")
-endif()
+message(STATUS "fetch GTest from https://github.com/google/googletest.git")
+include(FetchContent)
+FetchContent_Declare(
+    googletest
+    GIT_REPOSITORY https://github.com/google/googletest.git
+    GIT_TAG release-1.11.0
+)
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+set(BUILD_GMOCK ON CACHE BOOL "" FORCE)
+set(BUILD_GTEST ON CACHE BOOL "" FORCE)
+FetchContent_MakeAvailable(googletest)
+set(GMOCK_INCLUDE_DIR ${CMAKE_BINARY_DIR}/_deps/googletest-src/googlemock/include/)
+set(GTEST_INCLUDE_DIR ${CMAKE_BINARY_DIR}/_deps/googletest-src/googletest/include/)
+set(GTEST_LIBRARIES gtest_main)
+set(GMOCK_LIBRARIES gmock_main)
 
 message(STATUS "GTest: ${GTEST_INCLUDE_DIR}, ${GTEST_LIBRARIES}")
 message(STATUS "GMock: ${GMOCK_INCLUDE_DIR}, ${GMOCK_LIBRARIES}")

third_party_module/stdmodules/functional.cppm

@@ -20,6 +20,8 @@ export namespace std {
     operator==(const std::function<T>& __f, std::nullptr_t) noexcept {
         return __f == nullptr;
     }
+#else
+    using std::operator==;
 #endif
 }
 

third_party_module/stdmodules/type_traits.cppm

@@ -55,8 +55,4 @@ export namespace std {
 
     using std::invoke_result;
     using std::invoke_result_t;
-#if defined(__GLIBCXX__) || defined(__GLIBCPP__)
-    using std::result_of_t;
-    using std::result_of;
-#endif
 }