4.1

1 files changed, 77 insertions, 0 deletions

diff --git a/zen/scope_guard.h b/zen/scope_guard.h
new file mode 100644
index 00000000..d3633284
--- /dev/null
+++ b/zen/scope_guard.h
@@ -0,0 +1,77 @@
+// **************************************************************************
+// * This file is part of the zenXML project. It is distributed under the   *
+// * Boost Software License, Version 1.0. See accompanying file             *
+// * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.       *
+// * Copyright (C) 2011 ZenJu (zhnmju123 AT gmx.de)                         *
+// **************************************************************************
+
+#ifndef ZEN_SCOPEGUARD_8971632487321434
+#define ZEN_SCOPEGUARD_8971632487321434
+
+//best of Zen, Loki and C++11
+
+namespace zen
+{
+//Scope Guard
+/*
+    zen::ScopeGuard lockAio = zen::makeGuard([&]() { ::CancelIo(hDir); });
+		...
+	lockAio.dismiss();
+*/
+
+//Scope Exit
+/*
+	ZEN_ON_BLOCK_EXIT(::CloseHandle(hDir));
+*/
+
+class ScopeGuardBase
+{
+public:
+    void dismiss() const { dismissed_ = true; }
+
+protected:
+    ScopeGuardBase() : dismissed_(false) {}
+    ScopeGuardBase(const ScopeGuardBase& other) : dismissed_(other.dismissed_) { other.dismissed_ = true; } //take over responsibility
+    ~ScopeGuardBase() {}
+
+    bool isDismissed() const { return dismissed_; }
+
+private:
+    ScopeGuardBase& operator=(const ScopeGuardBase&); // = delete;
+
+    mutable bool dismissed_;
+};
+
+
+template <typename F>
+class ScopeGuardImpl : public ScopeGuardBase
+{
+public:
+    ScopeGuardImpl(F fun) : fun_(fun) {}
+
+    ~ScopeGuardImpl()
+    {
+        if (!this->isDismissed())
+            try
+            {
+                fun_();
+            }
+            catch (...) {}
+    }
+
+private:
+    F fun_;
+};
+
+typedef const ScopeGuardBase& ScopeGuard;
+
+template <class F> inline
+ScopeGuardImpl<F> makeGuard(F fun) { return ScopeGuardImpl<F>(fun); }
+}
+
+#define ZEN_CONCAT_SUB(X, Y) X ## Y
+#define ZEN_CONCAT(X, Y) ZEN_CONCAT_SUB(X, Y)
+
+#define ZEN_ON_BLOCK_EXIT(X) zen::ScopeGuard ZEN_CONCAT(dummy, __LINE__) = zen::makeGuard([&](){X;}); (void)ZEN_CONCAT(dummy, __LINE__);
+
+#endif //ZEN_SCOPEGUARD_8971632487321434