initial

cxx-shared/shared/defer.hpp

@@ -0,0 +1,30 @@
+#pragma once
+#include <utility>
+
+template <typename Callable>
+class DeferHolder {
+public:
+    explicit DeferHolder(Callable&& callable) noexcept: callable_(std::forward<Callable>(callable)) { }
+
+    ~DeferHolder() {
+        callable_();
+    }
+
+private:
+    Callable callable_;
+};
+
+class Defer {
+public:
+    constexpr Defer() noexcept = default;
+    constexpr ~Defer() noexcept = default;
+
+    template <typename Callable>
+    DeferHolder<Callable> operator%(Callable&& cb) {
+        return DeferHolder<Callable>{std::forward<Callable>(cb)};
+    }
+};
+
+#define COMMON_CAT_(x, y) x##y
+#define COMMON_CAT(x, y) COMMON_CAT_(x, y)
+#define defer auto COMMON_CAT(_defer_instance_, __LINE__) = Defer{} % [&]()