Feature: generator (#43)

.github/workflows/code_testing.yaml

@@ -12,12 +12,12 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - os: ubuntu-22.04
-            compiler: clang-15
           - os: ubuntu-22.04
             compiler: clang-16
           - os: ubuntu-22.04
             compiler: clang-17
+          - os: ubuntu-22.04
+            compiler: clang-18
 
           - os: ubuntu-22.04
             compiler: gcc-12
@@ -30,7 +30,7 @@ jobs:
         shell: bash
 
     steps:
-      - name: Add repos for for gcc-13 and clang-16
+      - name: Add repos for for gcc-13 and clang-16,..
         uses: dice-group/cpp-conan-release-reusable-workflow/.github/actions/setup_apt@main
 
       - name: Install CMake
@@ -66,7 +66,7 @@ jobs:
         uses: dice-group/cpp-conan-release-reusable-workflow/.github/actions/add_conan_provider@main
 
       - name: Configure CMake
-        run: cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=On -DBUILD_EXAMPLES=On -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=conan_provider.cmake -DCONAN_INSTALL_ARGS="--build=missing;-o=boost/*:header_only=True" -G Ninja -B build .
+        run: cmake -DCMAKE_CXX_FLAGS="-fsanitize=address,undefined" -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=On -DBUILD_EXAMPLES=On -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=conan_provider.cmake -G Ninja -B build .
         env:
           CC: ${{ steps.install_cc.outputs.cc }}
           CXX: ${{ steps.install_cc.outputs.cxx }}

CMakeLists.txt

@@ -10,6 +10,10 @@ project(
 option(BUILD_TESTING "build tests" OFF)
 option(BUILD_EXAMPLES "build examples" OFF)
 
+if (PROJECT_IS_TOP_LEVEL)
+    set(CONAN_INSTALL_ARGS "${CONAN_INSTALL_ARGS};-o=boost/*:header_only=True")
+endif ()
+
 # conan requires cmake build type to be specified and it is generally a good idea
 if (NOT EXISTS ${CMAKE_CURRENT_BINARY_DIR}/CMakeCache.txt)
   if (NOT CMAKE_BUILD_TYPE)

README.md

@@ -10,6 +10,10 @@ It contains:
 - `for_{types,values,range}`: Compile time for loops for types, values or ranges
 - `polymorphic_allocator`: Like `std::pmr::polymorphic_allocator` but with static dispatch
 - `DICE_DEFER`/`DICE_DEFER_TO_SUCCES`/`DICE_DEFER_TO_FAIL`: On-the-fly RAII for types that do not support it natively (similar to go's `defer` keyword)
+- `overloaded`: Composition for `std::variant` visitor lambdas
+- `flex_array`: A combination of `std::array` and `std::span`
+- `tuple_algorithms`: Some algorithms for iterating tuples
+- `generator`: The reference implementation of `std::generator` from [P2502R2](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2502r2.pdf)
 
 ## Usage
 
@@ -71,6 +75,13 @@ Some algorithms for iterating tuples, for example `tuple_fold` a fold/reduce imp
 A combination of `std::array` and `std::span` where the size is either statically known or a runtime variable
 depending on the `extent` template parameter
 
+### `generator`
+The reference implementation of `std::generator` from [P2502R2](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2502r2.pdf).
+By default, the generator and corresponding utilities are exported under the `dice::template_library::` namespace.
+If you want this generator to serve as a drop in replacement for `std::generator` until it arrives
+use `#define DICE_TEMPLATELIBRARY_GENERATOR_STD_COMPAT 1` before including the generator header. That will export
+all generator related things under namespace `std::`.
+
 ### Further Examples
 
 Compilable code examples can be found in [examples](./examples). The example build requires the cmake

examples/CMakeLists.txt

@@ -58,3 +58,10 @@ target_link_libraries(example_flex_array
         PRIVATE
         dice-template-library::dice-template-library
 )
+
+add_executable(example_generator
+        example_generator.cpp)
+target_link_libraries(example_generator
+        PRIVATE
+        dice-template-library::dice-template-library
+)

examples/example_generator.cpp

@@ -0,0 +1,46 @@
+#include <iostream>
+#include <string>
+
+#include <dice/template-library/generator.hpp>
+
+namespace dtl = dice::template_library;
+
+template<typename T>
+struct Tree {
+	T value;
+	Tree *left = nullptr;
+	Tree *right = nullptr;
+
+	[[nodiscard]] dtl::generator<T const &> traverse_inorder() const {
+		if (left != nullptr) {
+			co_yield dtl::ranges::elements_of(left->traverse_inorder());
+		}
+
+		co_yield value;
+
+		if (right != nullptr) {
+			co_yield dtl::ranges::elements_of(right->traverse_inorder());
+		}
+	}
+};
+
+int main() {
+	//    D
+	//  B    F
+	// A C  E G
+	Tree<char> leaf1{'A'};
+	Tree<char> leaf2{'C'};
+	Tree<char> leaf3{'E'};
+	Tree<char> leaf4{'G'};
+	Tree<char> branch1{'B', &leaf1, &leaf2};
+	Tree<char> branch2{'F', &leaf3, &leaf4};
+	Tree<char> root{'D', &branch1, &branch2};
+
+	std::string output;
+	for (char const x : root.traverse_inorder()) {
+		output.push_back(x);
+	}
+
+	assert(output == "ABCDEFG");
+	std::cout << output << '\n';
+}