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