added a module and corresponding tests

.github/workflows/linux.yml

@@ -5,29 +5,7 @@ name: Linux Build
 
 on:
   push:
-    branches: ["main"]
-    paths:
-      - "include/**"
-      - "src/**"
-      - "tests/**"
-      - "examples/**"
-      - "cmake/**"
-      - "Makefile"
-      - "CMakePresets.json"
-      - "CMakeLists.txt"
-      - ".github/workflows/linux.yml"
   pull_request:
-    branches: ["main"]
-    paths:
-      - "include/**"
-      - "src/**"
-      - "tests/**"
-      - "examples/**"
-      - "cmake/**"
-      - "Makefile"
-      - "CMakePresets.json"
-      - "CMakeLists.txt"
-      - ".github/workflows/linux.yml"
 
 jobs:
   build:
@@ -38,7 +16,8 @@ jobs:
       matrix:
         # TODO: sanitizer: [debug, release, asan, usan, tsan, lsan, msan]
         preset: [debug, release]
-        compiler: [g++-14, clang++-19]
+        # TODO: compiler: [g++-15, clang++-19]
+        compiler: [clang++-19]
 
     steps:
       - uses: actions/checkout@v4

.github/workflows/macos.yml

@@ -5,29 +5,7 @@ name: Macos Build
 
 on:
   push:
-    branches: ["main"]
-    paths:
-      - "include/**"
-      - "src/**"
-      - "tests/**"
-      - "examples/**"
-      - "cmake/**"
-      - "Makefile"
-      - "CMakePresets.json"
-      - "CMakeLists.txt"
-      - ".github/workflows/macos.yml"
   pull_request:
-    branches: ["main"]
-    paths:
-      - "include/**"
-      - "src/**"
-      - "tests/**"
-      - "examples/**"
-      - "cmake/**"
-      - "Makefile"
-      - "CMakePresets.json"
-      - "CMakeLists.txt"
-      - ".github/workflows/macos.yml"
 
 jobs:
   build:
@@ -37,8 +15,8 @@ jobs:
 
       matrix:
         preset: [debug, release]
-        # TODO: compiler: [g++, clang++-19]
-        compiler: [g++, clang++-18]
+        # TODO: compiler: [g++-15, clang++-19]
+        compiler: [clang++-19]
 
     steps:
       - uses: actions/checkout@v4
@@ -47,23 +25,20 @@ jobs:
         # if: startsWith(matrix.compiler, 'clang')
         uses: aminya/setup-cpp@v1
         with:
-          # TODO: compiler: llvm-19
-          # clangtidy: true
-          # cmake: true
           ninja: true
 
       - name: Install llvm-19
         if: startsWith(matrix.compiler, 'clang')
         run: |
           brew install llvm@19 || echo ignored
 
-      - name: macos clang++-18 ${{ matrix.preset }}
+      - name: macos clang++-19 ${{ matrix.preset }}
         if: startsWith(matrix.compiler, 'clang')
-        run: CXX=$(brew --prefix llvm@18)/bin/clang++ cmake --workflow --preset ${{ matrix.preset }}
+        run: CXX=$(brew --prefix llvm@19)/bin/clang++ cmake --workflow --preset ${{ matrix.preset }}
 
-      - name: macos clang++-18 sanitizer
+      - name: macos clang++-19 sanitizer
         if: startsWith(matrix.compiler, 'clang') && startsWith(matrix.preset, 'debug')
-        run: CXX=$(brew --prefix llvm@18)/bin/clang++ make all
+        run: CXX=$(brew --prefix llvm@19)/bin/clang++ make all
 
       - name: macos g++ ${{ matrix.preset }}
         if: startsWith(matrix.compiler, 'g++')

.github/workflows/windows.yml

@@ -5,27 +5,7 @@ name: Windows Build
 
 on:
   push:
-    branches: ["main"]
-    paths:
-      - "include/**"
-      - "src/**"
-      - "tests/**"
-      - "examples/**"
-      - "cmake/**"
-      - "CMakePresets.json"
-      - "CMakeLists.txt"
-      - ".github/workflows/windows.yml"
   pull_request:
-    branches: ["main"]
-    paths:
-      - "include/**"
-      - "src/**"
-      - "tests/**"
-      - "examples/**"
-      - "cmake/**"
-      - "CMakePresets.json"
-      - "CMakeLists.txt"
-      - ".github/workflows/windows.yml"
 
 jobs:
   build:

CMakeLists.txt

@@ -3,14 +3,18 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 # cmake-format: on
 
-cmake_minimum_required(VERSION 3.25...3.31)
+cmake_minimum_required(VERSION 3.30...3.31)
 
-project(beman_execution26 VERSION 0.0.1 LANGUAGES CXX)
+project(beman_execution26 VERSION 0.1.0 LANGUAGES CXX)
 
 if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_BINARY_DIR})
   message(FATAL_ERROR "In-source builds are not allowed!")
 endif()
 
+# Note that scanning is only performed if C++20 or higher is enabled for the target. Scanning for modules in the target's
+# sources belonging to file sets of type CXX_MODULES is always performed.
+# not needed: set(CMAKE_CXX_SCAN_FOR_MODULES ON)
+
 set(TARGET_NAME execution26)
 set(TARGET_NAMESPACE beman) # FIXME: not used in install(EXPORT ...) CK?
 set(TARGET_PREFIX ${TARGET_NAMESPACE}.${TARGET_NAME})
@@ -19,6 +23,9 @@ set(TARGET_ALIAS ${TARGET_LIBRARY}::${TARGET_LIBRARY})
 set(TARGET_PACKAGE_NAME ${PROJECT_NAME}-config)
 set(TARGETS_EXPORT_NAME ${PROJECT_NAME}-targets)
 
+# This variable is a special case of the more-general CMAKE_<CONFIG>_POSTFIX variable for the DEBUG configuration.
+set(CMAKE_DEBUG_POSTFIX D)
+
 include(GNUInstallDirs)
 set(INSTALL_CONFIGDIR ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME})
 
@@ -55,7 +62,7 @@ if(CMAKE_BUILD_TYPE STREQUAL Debug)
     ENABLE_SANITIZER_POINTER_COMPARE
     ENABLE_SANITIZER_POINTER_SUBTRACT
     ENABLE_CONTROL_FLOW_PROTECTION
-    ENABLE_STACK_PROTECTION
+    # XXX ENABLE_STACK_PROTECTION
     ENABLE_OVERFLOW_PROTECTION
     # ENABLE_ELF_PROTECTION
     # ENABLE_RUNTIME_SYMBOLS_RESOLUTION
@@ -85,7 +92,7 @@ include(CMakePackageConfigHelpers)
 write_basic_package_version_file(
   ${CMAKE_CURRENT_BINARY_DIR}/${TARGET_PACKAGE_NAME}-version.cmake
   VERSION ${CMAKE_PROJECT_VERSION}
-  COMPATIBILITY AnyNewerVersion
+  COMPATIBILITY SameMajorVersion
 )
 
 configure_package_config_file(

cmake/CMakeGenericPresets.json

@@ -12,7 +12,7 @@
           "type": "path",
           "value": "${sourceDir}/stagedir"
         },
-        "CMAKE_CXX_EXTENSIONS": false,
+        "CMAKE_CXX_EXTENSIONS": true,
         "CMAKE_CXX_STANDARD": "23",
         "CMAKE_CXX_STANDARD_REQUIRED": true,
         "CMAKE_EXPORT_COMPILE_COMMANDS": true,

examples/CMakeLists.txt

@@ -6,6 +6,7 @@
 list(
   APPEND
   EXAMPLES
+  modules
   playground
   sender-demo
   when_all-cancel

examples/modules.cpp

@@ -0,0 +1,20 @@
+// examples/modules.cpp                                               -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+// import std;
+#include <iostream>
+#include <string>
+#if __cpp_modules < 201907L
+#include <beman/execution26/execution.hpp>
+#else
+import beman_execution26;
+#endif
+
+namespace ex = beman::execution26;
+
+int main() {
+    auto [result] = ex::sync_wait(ex::when_all(ex::just(std::string("hello, ")), ex::just(std::string("world"))) |
+                                  ex::then([](const auto& s1, const auto& s2) { return s1 + s2; }))
+                        .value_or(std::tuple(std::string("oops")));
+    std::cout << "result='" << result << "'\n";
+}

include/beman/execution26/execution.hpp

@@ -20,6 +20,7 @@
 #include <beman/execution26/detail/operation_state.hpp>
 #include <beman/execution26/detail/sender.hpp>
 #include <beman/execution26/detail/sender_in.hpp>
+//-dk:TODO #include <beman/execution26/detail/sender_to.hpp>
 #include <beman/execution26/detail/scheduler.hpp>
 #include <beman/execution26/detail/receiver.hpp>
 #include <beman/execution26/detail/valid_completion_for.hpp>
@@ -37,6 +38,7 @@
 #include <beman/execution26/detail/start.hpp>
 #include <beman/execution26/detail/connect.hpp>
 #include <beman/execution26/detail/schedule.hpp>
+#include <beman/execution26/detail/schedule_result_t.hpp>
 
 #include <beman/execution26/detail/continues_on.hpp>
 #include <beman/execution26/detail/into_variant.hpp>

src/beman/execution26/CMakeLists.txt

@@ -7,7 +7,8 @@ add_library(${TARGET_LIBRARY} STATIC)
 add_library(${TARGET_ALIAS} ALIAS ${TARGET_LIBRARY})
 
 if(CMAKE_BUILD_TYPE STREQUAL Debug)
-  target_link_libraries(${TARGET_LIBRARY} PUBLIC $<BUILD_INTERFACE:${TARGET_LIBRARY}_project_options>)
+  # NOTE: Sanitizer or gcov is not possible for CXX_MODULES! CK
+  # XXX target_link_libraries(${TARGET_LIBRARY} PUBLIC $<BUILD_INTERFACE:${TARGET_LIBRARY}_project_options>)
   target_link_libraries(${TARGET_LIBRARY} PUBLIC $<BUILD_INTERFACE:${TARGET_LIBRARY}_project_warnings>)
 endif()
 
@@ -16,7 +17,6 @@ cmake_print_variables(TARGET_ALIAS TARGET_LIBRARY TARGET_PREFIX PROJECT_SOURCE_D
 
 target_sources(
   ${TARGET_LIBRARY}
-  PRIVATE execution.cpp
   PUBLIC FILE_SET
          ${TARGET_LIBRARY}_public_headers
          TYPE
@@ -188,18 +188,27 @@ target_compile_features(${TARGET_LIBRARY} PUBLIC
   "$<$<NOT:$<COMPILE_FEATURES:cxx_std_26>>:cxx_std_23>"
 )
 
+target_sources(
+  ${TARGET_LIBRARY}
+  PUBLIC FILE_SET ${TARGET_LIBRARY}_modules
+         TYPE CXX_MODULES FILES execution.cppm
+)
+
 install(
   TARGETS ${TARGET_LIBRARY}
-  EXPORT ${TARGETS_EXPORT_NAME}1
-  ARCHIVE DESTINATION lib/$<CONFIG>
+  EXPORT ${TARGETS_EXPORT_NAME}
+  ARCHIVE # XXX DESTINATION lib/$<CONFIG>
+  FILE_SET ${TARGET_LIBRARY}_modules
+    # There's currently no convention for this location
+    DESTINATION ${INSTALL_CONFIGDIR}/src
   FILE_SET ${TARGET_LIBRARY}_public_headers
   FILE_SET ${TARGET_LIBRARY}_detail_headers
 )
-# cmake-format: on
 
 install(
-  EXPORT ${TARGETS_EXPORT_NAME}1
-  FILE ${TARGETS_EXPORT_NAME}.cmake
+  EXPORT ${TARGETS_EXPORT_NAME}
   DESTINATION "${INSTALL_CONFIGDIR}"
+  CXX_MODULES_DIRECTORY .
   NAMESPACE ${TARGET_LIBRARY}::
 )
+# cmake-format: on