Changeset: 2 Work on moving infrastruture to this project

1 files changed, 53 insertions, 0 deletions

diff --git a/source/ScopeGuard.hpp b/source/ScopeGuard.hpp
new file mode 100644
index 0000000..b4a1749
--- /dev/null
+++ b/source/ScopeGuard.hpp
@@ -0,0 +1,53 @@
+#pragma once
+
+#include "Macros.hpp"
+
+#include <utility>
+
+template <class TCleanupFunc>
+class ScopeGuard {
+private:
+	TCleanupFunc mFunc;
+	bool mDismissed = false;
+
+public:
+	/// Specifically left this implicit so that constructs like
+	/// \code
+	/// ScopeGuard sg = [&]() { res.Cleanup(); };
+	/// \endcode
+	/// would work. It is highly discourage and unlikely that one would want to use ScopeGuard as a function
+	/// parameter, so the normal argument that implicit conversion are harmful doesn't really apply here.
+	// Deliberately not explicit to allow usages like: ScopeGuard var = lambda;
+	ScopeGuard(TCleanupFunc&& function) noexcept
+		: mFunc{ std::move(function) } {
+	}
+
+	~ScopeGuard() noexcept {
+		if (!mDismissed) {
+			mFunc();
+		}
+	}
+
+	ScopeGuard(const ScopeGuard&) = delete;
+	ScopeGuard& operator=(const ScopeGuard&) = delete;
+
+	ScopeGuard(ScopeGuard&& that) noexcept
+		: mFunc{ std::move(that.mFunc) } {
+		that.Cancel();
+	}
+
+	ScopeGuard& operator=(ScopeGuard&& that) noexcept {
+		if (!mDismissed) {
+			mFunc();
+		}
+		this->mFunc = std::move(that.mFunc);
+		this->cancelled = std::exchange(that.cancelled, true);
+	}
+
+	void Dismiss() noexcept {
+		mDismissed = true;
+	}
+};
+
+#define SCOPE_GUARD(name) ScopeGuard name = [&]()
+#define DEFER ScopeGuard UNIQUE_NAME(scopeGuard) = [&]()