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yielding · yielding · commit e2fdb6362492 · 2025-04-14T08:33:42.000+09:00
diff --git a/cpp.boost/variant2.shape/CMakeLists.txt b/cpp.boost/variant2.shape/CMakeLists.txt
@@ -0,0 +1,26 @@
+cmake_minimum_required (VERSION 3.30.0)
+
+project (main)
+
+set (CMAKE_CXX_STANDARD 26)
+set (CMAKE_CXX_COMPILER clang++)
+set (CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+set (SOURCES
+  main.cpp
+)
+
+include_directories (
+  /usr/local/include
+  /opt/homebrew/include
+  ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+link_directories (
+  /usr/local/lib
+  /opt/homebrew/lib
+)
+
+add_executable (main
+  ${SOURCES}
+)
diff --git a/cpp.boost/variant2.shape/main.cpp b/cpp.boost/variant2.shape/main.cpp
@@ -0,0 +1,41 @@
+#include <boost/variant2/variant.hpp>
+#include <vector>
+#include <print>
+
+using namespace std;
+using namespace boost::variant2;
+
+struct Recangle
+{
+  double area() const { return width * height; }
+
+  int width;
+  int height;
+};
+
+struct Circle
+{
+  double area() const { return 3.14 * radius * radius; }
+  int radius;
+};
+
+double total_area(const vector<variant<Recangle, Circle>>& shapes)
+{
+  double total = 0;
+  for (const auto& shape : shapes)
+    total += visit([](auto const& s) { return s.area(); }, shape);
+
+  return total;
+}
+
+int main(int argc, char* argv[])
+{
+  vector<variant<Recangle, Circle>> shapes;
+
+  shapes.push_back(Recangle{5, 10});
+  shapes.push_back(Circle{3});
+
+  println("Total area: {}", total_area(shapes));
+
+  return 0;
+}
