Implement modules support

.github/workflows/ci_tests.yml

@@ -48,7 +48,7 @@ jobs:
                       "tests": [
                         "Debug.Default", "Release.Default", "Release.TSan",
                         "Release.MaxSan", "Debug.Werror", "Debug.Dynamic",
-                        "Debug.Coverage"
+                        "Debug.Coverage", "Debug.-DBEMAN_TAKE_BEFORE_USE_MODULES=On"
                       ]
                     }
                   ]
@@ -82,7 +82,7 @@ jobs:
                     { "stdlibs": ["libstdc++", "libc++"],
                       "tests": [
                         "Debug.Default", "Release.Default", "Release.TSan",
-                        "Release.MaxSan", "Debug.Werror", "Debug.Dynamic"
+                        "Release.MaxSan", "Debug.Werror", "Debug.Dynamic", "Debug.-DBEMAN_TAKE_BEFORE_USE_MODULES=On"
                       ]
                     }
                   ]

CMakeLists.txt

@@ -2,6 +2,8 @@
 
 cmake_minimum_required(VERSION 3.30...4.3)
 
+include(infra/cmake/enable-experimental-import-std.cmake)
+
 project(
     beman.take_before
     DESCRIPTION "take_before_view"
@@ -24,21 +26,58 @@ option(
 )
 
 # for find of beman_install_library and configure_build_telemetry
+option(
+    BEMAN_TAKE_BEFORE_USE_MODULES
+    "Provide beman.take_before as a C++ module"
+    OFF
+)
+
+if(BEMAN_TAKE_BEFORE_USE_MODULES)
+    set(CMAKE_CXX_SCAN_FOR_MODULES ON)
+endif()
+
+configure_file(
+    "${PROJECT_SOURCE_DIR}/include/beman/take_before/config_generated.hpp.in"
+    "${PROJECT_BINARY_DIR}/include/beman/take_before/config_generated.hpp"
+    @ONLY
+)
+
 include(infra/cmake/beman-install-library.cmake)
 include(infra/cmake/BuildTelemetryConfig.cmake)
 
-add_library(beman.take_before INTERFACE)
+if(BEMAN_TAKE_BEFORE_USE_MODULES)
+    add_library(beman.take_before STATIC)
+else()
+    add_library(beman.take_before INTERFACE)
+endif()
 add_library(beman::take_before ALIAS beman.take_before)
 
-target_sources(
-    beman.take_before
-    PUBLIC FILE_SET HEADERS BASE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include"
-)
-
-set_target_properties(
-    beman.take_before
-    PROPERTIES VERIFY_INTERFACE_HEADER_SETS ${PROJECT_IS_TOP_LEVEL}
-)
+if(BEMAN_TAKE_BEFORE_USE_MODULES)
+    target_sources(
+        beman.take_before
+        PUBLIC
+            FILE_SET CXX_MODULES
+            FILE_SET HEADERS
+                BASE_DIRS
+                    "${CMAKE_CURRENT_SOURCE_DIR}/include"
+                    "${CMAKE_CURRENT_BINARY_DIR}/include"
+    )
+    set_target_properties(beman.take_before PROPERTIES CXX_MODULE_STD ON)
+    target_compile_features(beman.take_before PUBLIC cxx_std_23)
+else()
+    target_sources(
+        beman.take_before
+        PUBLIC
+            FILE_SET HEADERS
+                BASE_DIRS
+                    "${CMAKE_CURRENT_SOURCE_DIR}/include"
+                    "${CMAKE_CURRENT_BINARY_DIR}/include"
+    )
+    set_target_properties(
+        beman.take_before
+        PROPERTIES VERIFY_INTERFACE_HEADER_SETS ${PROJECT_IS_TOP_LEVEL}
+    )
+endif()
 
 add_subdirectory(include/beman/take_before)
 

examples/CMakeLists.txt

@@ -12,4 +12,7 @@ foreach(example ${ALL_EXAMPLES})
     add_executable(${example})
     target_sources(${example} PRIVATE ${example}.cpp)
     target_link_libraries(${example} PRIVATE beman::take_before)
+    if(BEMAN_TAKE_BEFORE_USE_MODULES)
+        set_target_properties(${example} PROPERTIES CXX_MODULE_STD ON)
+    endif()
 endforeach()

examples/take_before_compose.cpp

@@ -1,11 +1,21 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 // examples/take_before_compose.cpp
 
-#include <beman/take_before/take_before.hpp>
+#include <beman/take_before/config.hpp>
+
+#if BEMAN_TAKE_BEFORE_USE_MODULES()
+
+import std;
+
+#else
 
-#include <iostream>
-#include <ranges>
-#include <vector>
+    #include <iostream>
+    #include <ranges>
+    #include <vector>
+
+#endif
+
+#include <beman/take_before/take_before.hpp>
 
 namespace btb = beman::take_before;
 

examples/take_before_direct_usage.cpp

@@ -1,10 +1,20 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 // examples/take_before_direct_usage.cpp
 
-#include <beman/take_before/take_before.hpp>
+#include <beman/take_before/config.hpp>
+
+#if BEMAN_TAKE_BEFORE_USE_MODULES()
+
+import std;
+
+#else
 
-#include <iostream>
-#include <vector>
+    #include <iostream>
+    #include <vector>
+
+#endif
+
+#include <beman/take_before/take_before.hpp>
 
 namespace btb = beman::take_before;
 

examples/take_before_ntbs.cpp

@@ -1,8 +1,19 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 // examples/take_before_ntbs.cpp
 
+#include <beman/take_before/config.hpp>
+
+#if BEMAN_TAKE_BEFORE_USE_MODULES()
+
+import std;
+
+#else
+
+    #include <iostream>
+
+#endif
+
 #include <beman/take_before/take_before.hpp>
-#include <iostream>
 
 namespace btb = beman::take_before;
 

examples/take_before_text_split.cpp

@@ -4,13 +4,23 @@
 // This example demonstrates the usage of beman::take_before in a range-printer.
 // Requires: range support (C++20).
 
-#include <beman/take_before/take_before.hpp>
+#include <beman/take_before/config.hpp>
+
+#if BEMAN_TAKE_BEFORE_USE_MODULES()
+
+import std;
+
+#else
 
-#include <algorithm>
-#include <iostream>
-#include <ranges>
-#include <string>
-#include <vector>
+    #include <algorithm>
+    #include <iostream>
+    #include <ranges>
+    #include <string>
+    #include <vector>
+
+#endif
+
+#include <beman/take_before/take_before.hpp>
 
 namespace btb = beman::take_before;
 

include/beman/take_before/CMakeLists.txt

@@ -1,3 +1,24 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-target_sources(beman.take_before PUBLIC FILE_SET HEADERS FILES take_before.hpp)
+if(BEMAN_TAKE_BEFORE_USE_MODULES)
+    target_sources(
+        beman.take_before
+        PUBLIC
+            FILE_SET CXX_MODULES FILES take_before.cppm
+            FILE_SET HEADERS
+                FILES
+                    config.hpp
+                    take_before.hpp
+                    "${PROJECT_BINARY_DIR}/include/beman/take_before/config_generated.hpp"
+    )
+else()
+    target_sources(
+        beman.take_before
+        PUBLIC
+            FILE_SET HEADERS
+                FILES
+                    config.hpp
+                    take_before.hpp
+                    "${PROJECT_BINARY_DIR}/include/beman/take_before/config_generated.hpp"
+    )
+endif()

include/beman/take_before/config.hpp

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef BEMAN_TAKE_BEFORE_CONFIG_HPP
+#define BEMAN_TAKE_BEFORE_CONFIG_HPP
+
+#if !defined(__has_include) || __has_include(<beman/take_before/config_generated.hpp>)
+    #include <beman/take_before/config_generated.hpp>
+#else
+    #define BEMAN_TAKE_BEFORE_USE_MODULES() 0
+#endif
+
+#endif

include/beman/take_before/config_generated.hpp.in

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef BEMAN_TAKE_BEFORE_CONFIG_GENERATED_HPP
+#define BEMAN_TAKE_BEFORE_CONFIG_GENERATED_HPP
+
+#cmakedefine01 BEMAN_TAKE_BEFORE_USE_MODULES()
+
+#endif

include/beman/take_before/take_before.cppm

@@ -0,0 +1,11 @@
+export module beman.take_before;
+
+import std;
+
+#define BEMAN_TAKE_BEFORE_INCLUDED_FROM_INTERFACE_UNIT
+export {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Winclude-angled-in-module-purview"
+#include <beman/take_before/take_before.hpp>
+#pragma clang diagnostic pop
+}

include/beman/take_before/take_before.hpp

@@ -3,15 +3,27 @@
 #ifndef BEMAN_TAKE_BEFORE_TAKE_BEFORE_HPP
 #define BEMAN_TAKE_BEFORE_TAKE_BEFORE_HPP
 
-#include <algorithm>
-#include <concepts>
-#include <memory>
-#include <optional>
-#include <ranges>
-#include <type_traits>
-#include <utility>
-
-// clang-format off
+#include <beman/take_before/config.hpp>
+
+#if BEMAN_TAKE_BEFORE_USE_MODULES() && !defined(BEMAN_TAKE_BEFORE_INCLUDED_FROM_INTERFACE_UNIT)
+
+import beman.take_before;
+
+#else
+
+    #if !BEMAN_TAKE_BEFORE_USE_MODULES()
+
+        #include <algorithm>
+        #include <concepts>
+        #include <memory>
+        #include <optional>
+        #include <ranges>
+        #include <type_traits>
+        #include <utility>
+
+    #endif // !BEMAN_TAKE_BEFORE_USE_MODULES()
+
+    // clang-format off
 #if __cpp_concepts > 202002L
    #error "C++20 concepts is required"
 #endif
@@ -30,8 +42,8 @@ using maybe_const = std::conditional_t<Const, const T, T>;
 // [range.utility.helpers] simple-view - exposition only
 template <class R>
 concept simple_view = std::ranges::view<R> && std::ranges::range<const R> &&
-                      std::same_as<std::ranges::iterator_t<R>, std::ranges::iterator_t<const R>> &&
-                      std::same_as<std::ranges::sentinel_t<R>, std::ranges::sentinel_t<const R>>;
+                      std::same_as<std::ranges::iterator_t<R>, std::ranges::iterator_t<const R> > &&
+                      std::same_as<std::ranges::sentinel_t<R>, std::ranges::sentinel_t<const R> >;
 
 // ============================================================================
 // tidy-obj concept for borrowed range optimization
@@ -53,7 +65,7 @@ using movable_box = std::optional<T>;
 template <std::ranges::view V, std::move_constructible T>
     requires std::ranges::input_range<V> && std::is_object_v<T> &&
              std::indirect_binary_predicate<std::ranges::equal_to, std::ranges::iterator_t<V>, const T*>
-class take_before_view : public std::ranges::view_interface<take_before_view<V, T>> {
+class take_before_view : public std::ranges::view_interface<take_before_view<V, T> > {
     template <bool>
     class sentinel; // exposition only
 
@@ -143,7 +155,7 @@ class take_before_view<V, T>::sentinel {
     sentinel() = default;
 
     constexpr sentinel(sentinel<!Const> s)
-        requires Const && std::convertible_to<std::ranges::sentinel_t<V>, std::ranges::sentinel_t<Base>>
+        requires Const && std::convertible_to<std::ranges::sentinel_t<V>, std::ranges::sentinel_t<Base> >
         : end_(std::move(s.end_)) {
         if constexpr (!tidy_obj<T>) {
             value_ = s.value_;
@@ -161,8 +173,10 @@ class take_before_view<V, T>::sentinel {
     }
 
     template <bool OtherConst = !Const>
-        requires std::sentinel_for<std::ranges::sentinel_t<Base>, std::ranges::iterator_t<maybe_const<OtherConst, V>>>
-    friend constexpr bool operator==(const std::ranges::iterator_t<maybe_const<OtherConst, V>>& x, const sentinel& y) {
+        requires std::sentinel_for<std::ranges::sentinel_t<Base>,
+                                   std::ranges::iterator_t<maybe_const<OtherConst, V> > >
+    friend constexpr bool operator==(const std::ranges::iterator_t<maybe_const<OtherConst, V> >& x,
+                                     const sentinel&                                             y) {
         if constexpr (tidy_obj<T>) {
             return y.end_ == x || T() == *x;
         } else {
@@ -183,7 +197,7 @@ take_before_view(R&&, T) -> take_before_view<std::ranges::views::all_t<R>, T>;
 
 namespace std::ranges {
 template <class V, class T>
-constexpr bool enable_borrowed_range<beman::take_before::take_before_view<V, T>> =
+constexpr bool enable_borrowed_range<beman::take_before::take_before_view<V, T> > =
     enable_borrowed_range<V> && beman::take_before::tidy_obj<T>;
 } // namespace std::ranges
 
@@ -241,12 +255,15 @@ struct take_before_fn {
     // Overload 3: single argument for pipe operator
     template <typename T>
     constexpr auto operator()(T&& value) const {
-        return detail::take_before_closure<std::decay_t<T>>(std::forward<T>(value));
+        return detail::take_before_closure<std::decay_t<T> >(std::forward<T>(value));
     }
 };
 
 inline constexpr take_before_fn take_before;
 
 } // namespace beman::take_before::views
 
+#endif // #if BEMAN_TAKE_BEFORE_USE_MODULES() &&
+       // !defined(BEMAN_TAKE_BEFORE_INCLUDED_FROM_INTERFACE_UNIT)
+
 #endif // BEMAN_TAKE_BEFORE_TAKE_BEFORE_HPP