初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/ThirdParty/include/CesiumUtility/ScopeGuard.h

@@ -0,0 +1,87 @@
+#pragma once
+
+#include <type_traits>
+#include <utility>
+
+namespace CesiumUtility {
+/**
+ * @brief A utility that will automatically call the lambda function when
+ * exiting a scope.
+ *
+ * @tparam ExitFunction The function type to be called when the guard is out of
+ * scope.
+ */
+template <typename ExitFunction> class ScopeGuard {
+public:
+  /**
+   * @brief Constructor.
+   *
+   * @param exitFunc The function type to be called when the guard is out
+   * of scope
+   */
+  template <
+      typename ExitFunctionArg,
+      typename std::enable_if_t<
+          !std::is_same_v<
+              std::remove_reference_t<std::remove_const_t<ExitFunctionArg>>,
+              ScopeGuard<ExitFunction>>,
+          int> = 0>
+  explicit ScopeGuard(ExitFunctionArg&& exitFunc)
+      : _callExitFuncOnDestruct{true},
+        _exitFunc{std::forward<ExitFunctionArg>(exitFunc)} {}
+
+  ScopeGuard(const ScopeGuard& rhs) = delete;
+
+  /**
+   * @brief Move constructor. The rhs will move its lambda to the lhs, and the
+   * rhs will not call its lambda upon exiting a scope
+   */
+  ScopeGuard(ScopeGuard&& rhs) noexcept
+      : _callExitFuncOnDestruct{rhs._callExitFuncOnDestruct},
+        _exitFunc{std::move(rhs._exitFunc)} {
+    rhs.release();
+  }
+
+  ScopeGuard& operator=(const ScopeGuard& rhs) = delete;
+
+  /**
+   * @brief Move assignment operator. The rhs will move its lambda to the lhs,
+   * and the rhs will not call its lambda upon exiting a scope
+   */
+  ScopeGuard& operator=(ScopeGuard&& rhs) noexcept {
+    if (&rhs != this) {
+      _callExitFuncOnDestruct = rhs._callExitFuncOnDestruct;
+      _exitFunc = std::move(rhs._exitFunc);
+      rhs.release();
+    }
+
+    return *this;
+  }
+
+  /**
+   * @brief Destructor. The guard will execute the lambda function when exiting
+   * a scope if it's not released
+   */
+  ~ScopeGuard() noexcept {
+    if (_callExitFuncOnDestruct) {
+      _exitFunc();
+    }
+  }
+
+  /**
+   * @brief Upon calling ScopeGuard::release(), the guard will not execute the
+   * lambda function when exiting a scope
+   */
+  void release() noexcept { _callExitFuncOnDestruct = false; }
+
+private:
+  bool _callExitFuncOnDestruct;
+  ExitFunction _exitFunc;
+};
+
+/** @brief Template deduction guide for \ref ScopeGuard to help the compiler
+ * figure out that the type of `ExitFunction` should be the type of the
+ * function passed to the constructor. */
+template <typename ExitFunction>
+ScopeGuard(ExitFunction) -> ScopeGuard<ExitFunction>;
+} // namespace CesiumUtility