Add SCOPE_EXIT macro to conveniently execute cleanup actions

src/common/CMakeLists.txt

@@ -51,6 +51,7 @@ set(HEADERS
             msg_handler.h
             platform.h
             scm_rev.h
+            scope_exit.h
             string_util.h
             swap.h
             symbols.h

src/common/scope_exit.h

@@ -0,0 +1,37 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+namespace detail {
+    template <typename Func>
+    struct ScopeExitHelper {
+        explicit ScopeExitHelper(Func&& func) : func(std::move(func)) {}
+        ~ScopeExitHelper() { func(); }
+
+        Func func;
+    };
+
+    template <typename Func>
+    ScopeExitHelper<Func> ScopeExit(Func&& func) { return ScopeExitHelper<Func>(std::move(func)); }
+}
+
+/**
+ * This macro allows you to conveniently specify a block of code that will run on scope exit. Handy
+ * for doing ad-hoc clean-up tasks in a function with multiple returns.
+ *
+ * Example usage:
+ * \code
+ * const int saved_val = g_foo;
+ * g_foo = 55;
+ * SCOPE_EXIT({ g_foo = saved_val; });
+ *
+ * if (Bar()) {
+ *     return 0;
+ * } else {
+ *     return 20;
+ * }
+ * \endcode
+ */
+#define SCOPE_EXIT(body) auto scope_exit_helper_##__LINE__ = detail::ScopeExit([&]() body)